Meet the Graysons!

[Bluelantern]

Bellow I will describe the Grayson clan templates.
In its most typical and "modal" format. The Grayson are family where the father, Stephen, ends up having children with multiple women. The family expands to a total of six children, by three different mothers, with the children being intended to be the main characters.

I divide the family into "branches" distinguished by parents:
Black branch: Arya and Ezra and their mother Mary Jane.
White branch: Franklyn, Meghan and Adam and their mother Sophia.
Green branch: Temperance and her mother Patience.
Gray branch: Stephen and his mother Ashley.
In each world the parents' surnames will be [color] + [something]: Whitepond, Whitewing, Whitehill, etc.

The Black Branch
Arya - First child between Stephen and Mary Jane.
Names: Ophelia Arya or Orpheus Aaron. Goes by the middle name.
Friendly and fun, but tends to be easily bored and often gets impulsive, she is well-meaning but might punch first and ask questions later if not guided well enough. Talent for dance and music. Dreams to be an action hero. Powers: Tends to get powers to react and move fast, often in the form of a "danger sense" plus a movement power.
PB: Meghan Ory and Aaron Taylor Johnson.

Anthony Ezra Blackwell
Tends to reign Arya's more punching-prone tendencies. Interests include history and the mental integrity, has a fear of amnesia. Also has tendencies for self-loathing, high-libido and less romantic interest, the later two feeding the former (due to being similar to their dad). A sort of “Florence Nightingale Effect” situation might also crop up, and will stick to a person that loves him, even if he doesn’t love back. Powers: Can heal minds against mental tampering.
PB: Edward Westwick

Franklyn Whitepond
Tends to like learning things, specially by talking with people, reading, he also very cheerful and friendly. Tends to have problem with making choices and settling for a final job/career. Also likely to develop some sort of madness. Franklyn is made of sunshine and rainbows compressed in a six feet tall package (okay, he is tall, but you see it is still compressed so it is a lot of sunshine and rainbows). Powers (original version): Copies skills, knowledge but not episodic memories of people around him.
PB: Skylar Maxon

Meghan Whitepond
Tends to be a healer with a difficult relationship with healing. She hates injury, and loves healing itself, but dislikes much of culture baggage associated with healers (being fragile and pure) exacerbated by being kidnapped at young age so her powers could be used against her will. Meghan evokes “Jerk with heart of gold” and takes it professional levels. Powers: Healing, temporarily grants regeneration to people and affect biological growth.
PB: Jessica Lowndes

Adam Whitepond
Tends to be a introverted artist/musician and the grayson-siblings mostly likely to “just want to be normal” and not get into the way of any sort of adventure unless the adventure gets him. Powers: Can animate eletronics and calming music.
PB: Skandar Keynes

Temperance Greengard
Temps loves doing new things and trying new hobbies and experiences (being her weakest point). She is the sibling that I have the most problem defining, partially because she doesn’t stabilize enough to be defined, she is flexible and the most likely to settle on a “rational fic protagonist”. Powers: Can copy a magical power. Can ward people against power drain.
PB: Nathalie Emmanuel

[anthusiasm]

Ooh, unusual family situations! And sibling relationships! Which siblings tend to be closest to each other, and which ones tend to harbor animosity towards each other?

Also, is Ophelia's mom a Game of Thrones fan?

[Bluelantern]

Yay! Questions!

(Ophelia prefers "Arya")

Ooh, unusual family situations! And sibling relationships! Which siblings tend to be closest to each other, and which ones tend to harbor animosity towards each other?

I am glad you asked!

Franklyn is the type of friendly person that can sometimes be too friendly if you aren't downright blunt with him, that said he gets along best with Temperance (both being the curious sorts). The others can find him somehow tiresome but no one really dislikes him, except maybe Meghan, but she has a high threshold for liking people. In general... I think he likes his siblings more than they like him.

Meghan, tends to be too defensive/agressive and guarded, I think her initial interactions with Arya would be a little antagonistic, but they will grow to have a deep relationship once they figured each other out. Additionally, Meghan and Arya are very similar, and most people assume they are full sisters or even twins if the heights match. She is pretty "sort of" neutral to Adam and Ezra (they don't get on her way), Franklyn sometimes annoys her and she has ups and downs with Temperance (who would fight back, unlike Franklyn)

Adam, I don't see him making very deep attachments with any of his siblings, but not in a negative way... he just wouldn't be prone to seek friendship there, specially given all the weirdness (due to the family situation or supernatural). He and Ezra would get along somehow well, since Ezra can be interested in similar things without the disrupting intensity that Franklyn and Temperance have.

Arya, I am thinking that these templates work in a way that Ezra can be Arya's twin or younger brother, with different results to their relationship. As her twin, Ezra would sort of contain Arya, working as a buffer between her and the outside world. In a sense, this makes them closer but less friendly. They can rely on each other, but they can't quite enjoy each other's presence as friends, specially because they don't have much in common. That all said, Arya isn't unfriendly or anything, she is just open, honest and tends to have Strong Opinions. Arya and Meghan get along (as mentioned above) because Arya has a backbone (which Meghan admires). Arya finds Franklyn funny, but doesn't have much in common with him and the other siblings. Temps sometimes will hang out with Arya to do something adventures but these moods don't tend to last enough to make the relationship deep.

Ezra, his relationship with Arya is elaborated above, just gonna add that Ezra admires Arya's integrity to he ideals and sometimes wish that for himself, even if not in the same shape. Ezra finds Franklyn friendly and well-meaning, but finds Franklyn too... excited-six-year-old. Meghan shares some bad traits with his twin and Ezra doesn't want to manage that. Adam is the very model of the perfect little sibling. Temperance is something between Franklyn and Adam, sometimes Temps will display interest on things that Ezra likes, and while she has enthusiasm, Temps knows to calm down and behave like an adult, circunstances might allow quite a friendship, possibly the best friendship between Ezra and one of the siblings.

Temperance. Original Temps was discovered later by the family, so this means an unpleasant start due to multiple levels of tensions, etc. I am going to describe the more... "neutral state" of how the relationships should go. Temps should get a long somehow well with Franklyn, better than any of the other siblings. Her reaction to Meghan could be described by "this girl needs to work her issues". Adam is okay, not exactly interesting, and his music can be enjoyable, but they don't seek each other very actively. Temps like Arya and Ezra on similar levels, and they even work well for as a set (high chances that one of them will want to do something that Temps want to do).

Also, is Ophelia's mom a Game of Thrones fan?

hum.... I don't think she would enjoy the TV series by herself, but she remarries and her second husband is a major nerd who would be a fan. I think Mary Jane finds the coincidence ironic and maybe annoying. I think I should mention that MJ resents her name and was trying to give her children dignified names. Arya actually dislikes being named after the Hamlet character.