A very interesting start. I'm a bit disappointed that you didn't take advantage of Sirius marrying Andromeda to make Tonks (Black now, I guess) Harry's age. Still, if Bonnie's a metamorphmagus I've got no complaints.
Looking forward to chapter 2.
Author's response
I've always liked Tonks being older than Harry so it didn't even cross my mind to change her to Harry's age (I did make her a little younger so she'd be at Hogwarts when he arrives).
I'm leaning more towards Bonnie following her dad's path. Maybe I'll make it into a latent talent on the side, I'll think about it. Hope you'll still read!