Miles Fairchild

(based on "Nanny." I made my own changes)
Miles is a strange teenager. He's calm, quiet, and strange. He loves his sister Flora very much. He can ride a horse and had a teacher, but he died.
Flora is Miles's younger sister, kind, sweet, little.
Millie is most likely their friend, but she lives with them in the same estate, her parents also died. In general, there is a very long story there.
Soon the children had a new nanny, since the previous one left without saying goodbye, as some kind of paranoid chaos was going on in the estate.
The thing is that their estate is inhabited by various spirits of dead souls.
Millie is calm, sometimes a little angry, funny, loves Flora like a sister, and Miles like a best friend, constantly watches movies or TV shows, or listens to music, plays electric guitar with Miles, and he plays drums. Every child in this estate does something: Miles rides a horse, Flora sits in the greenhouse, and Millie shoots guns. There is a basement under the stables, this is Millie's shooting gallery.
They also have a grandmother, Miss Grose, who does all the housework: washing dishes, cleaning, cooking, and cleaning up after the children (meaning the dishes after breakfast).
Millie hardly leaves her room, but not because she doesn't love anyone, she just likes it that way.