I love Isla and Mia as names, the others are lovely names too but I would go for Isla or Mia personally. Which are you swaying more towards?
That's the problem I can't decide. Mia was top of the list but then my SIL just had a baby and called her Leah and i'm thinking they sound very similar? Maybe it doesn't matter and i'm over thinking it
How close are you to your sister in law?
Mia and Leah do sound a little similar, but I don't think it's too much. Have you asked family members opinions to see what they think?
I do love the name Mia and working in a school I've found the girls I've worked with called Mia have been lovely, I've never worked with an Isla but do think it's a very pretty name. Same with Lily and Lila never actually worked with anyone with those names.