Here's a basic summary:
A is a 30-something who becomes a foster parent for B. B is 4 years old when she moves in with A, and is blind. B's mom is in jail, family is MIA... We get the background story, but the bulk of the story is 5 years later. B is 9, A is almost 40... B's mom comes back into the picture and wants to regain custody. There's a lot of courtroom time and counseling time deciding what is best for B.
SO... would you write the story from A's perspective (my gut instinct), in the 3rd person. Initially I thought about writing it from A's perspective, but then I think maybe to give the reader more sympathy toward ALL the characters it might be better to write in the 3rd person. I don't know, honestly, if I want my readers to be entirely on A's side (meaning as soon as B's mom appears, she's vilified to the reader) or not.
Thoughts?
Re: Which person should I write in--1st or 3rd?
It depends. A good close 3rd is just as good as a 1st and sometimes a little easier to write.
I'm not sure I'm following where 1st comes in here. Are you thinking of doing dual perspectives - one with A's story and one with B or B's Mom (or both)? that could be okay too, I dislike keeping that many voices in my head and I'm not a fan of reading them, but several authors have pulled it off with success. Ultimately, do what's most comfortable for you to write.
Keep in mind that sympathy for all the characters can be established through any point of view. Give B's mom a couple of humanizing moments in front of A. If the character is earnest about regaining custody and not just trying to get money or something, give her a moment when she does something undeniably sincere. Of course your main character can doubt her, as she should, but then the reader gets to make up their minds about B's mom.
Hope this isn't confusing, but I'm drinking wine, so... you know...