My headcaons I have for fethry and his siblings
Abner is the oldest (eight years older than fethry four years older than Mary) ,Mary is the middle(four years older than fethry) ,Fethry is the youngest
All three of them are biracial aka mixed, Lulu being African American and edier being white. Fethry looks more like his mother, while Abner looks more like his father, and Mary is a beautiful mix with lighter feathers and her hair works more like white hair.
I see abner as asexual and aromatic, Mary is straight but supports her brothers , fethry is pansexual
Growing up they lost their mother when Abner was thirteen and was left to take care of his nine year old sister and five year old brother. He was more of a parent to them then their own father was. Abner and his father fought constantly sometimes it would get bad to the point they were fighting each other fist to fist. When it came to school they went to a school where all grades went to the same school, which Abner liked so that way he could keep an eye on his siblings, and whatever free after school activity was there Abner would sign them up for, the longer he could keep them away from the house the better. One of these after school activities fethry was in was some kind of guitar lessons, which lead to fethry learning how to play perfect guitar. Whenever they had the chance they would go to grandma and grandpas house, they wouldn't say a word about what went on at home because they didn't want they're dad to get mad at them.
Gus: he's very close to Gus seeing how their the oldest out of all their cousins, Gus is one out of the two who really know what goes on at home and tries to get Abner to tell grandma but Abner is stubborn. Abner calls Gus mean names like "Fat ass", but gus doesn't take it to heart because he knows gus doesn't mean it.
Mary: he helps teaches her to fend for herself when Abner can't be there at home. Abner is very over protective of his sister and whatever boys comes in her way and he doesn't think the guy is good enough he'll quickly shut it down, which is the only thing Abner and edier could agree on
Fethry : He enjoys having fethry around and when he wants to get something off his mind he would definitely not mind fethry's yapping going on and on about random stuff to drain out his thoughts.
Della : as one of the two only girls in the family she enjoys having Della around and just being girls, going into the small tree house their grandpa built for them and just make fun of their brothers and cousins. And when they get older she makes Della god mother to her son dugan
Abner: although he's grateful for everything her big brother does for her, she would love to just hang out with her guy friends and go on a date but that's impossible to do when your brother and your dad are always over protective of you.
Fethry: Mary loves her baby brother and whenever she decides to sneek out to go meet up with Della when she comes and visits or when she goes to see a boy fethry always makes up an excuse and covers for her. And they surpriseingly have never been caught.
Gladestone: Gladstone had always felt like another brother to fethry ever since he could remember. He admired Gladstone's luck and wondered how he got it, and they became even closer once they moved in with Della and donald into scrooge's mansion.
Donald: He always knew donald didn't like having him around but that never bother fethry. He enjoyed going on adventures with donald and liked defeating pirates both sky and water with donald, donald always felt like a second dad to fethry even if he annoyed donald all the time.
Kildare: out of all his cousins Kildare was his absolute favorite having someone to connect to was always special especially when it came to the two of them. Kildare is the second one to know know what goes on at fethry's home and he swore to fethry that he wouldn't tell, although it always made him paranoid that those brusies on fethry weren't from fishing.
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I plan on writing a small fic from one of these headcanons not sure which one yet.