But to her, you are her father, and if you're not her bio-father you're still her stepfather
If everything has been good since they've been in the UK, maybe you should stop looking at the past and into the future instead
If the past will not go away, maybe try and get help from someone like 'Relate', but like Mick has said you've got a lot to lose.
Problems with kids remind me of the Cat Stevens song, father to son ..
I was once like you are now, and I know that it's not easy,
To be calm when you've found something going on.
But take your time, think a lot,
Why, think of everything you've got.
For you will still be here tomorrow, but your dreams may not.