I like the basic premise here. Your writing is a bit uneven, but
that's OK -- you're developing your skills here, so please don't stop!
There's a logic problem here: if you adopt someone, you aren't their
guardian; you're their mother or father. If you want to become
someone's guardian, then you don't adopt them, but they become your
"ward". When you revise this story (you do plan to revise it at
some point) I'd encourage you to think on that.