Don't try too hard to make her like you. Just talk to her naturally, ask her about her, what she does at school etc - don't try and swat up on things her age just to try and start a conversations. Never try and act like you're going to be her new mum or be over-the-top friendly with her on this first occassion by suggesting girly dates together. Also don't embarass her by being overly tactile or flirty with her dad.

The worst thing you can do with kids from tot to twenty is try too hard. They're like dogs, they can smell your fear and won't hesitate to capitalise on it! Accept that even if they've been apart for 15 years, she'd ideally like her mum and dad to still be together and that you're probably going to be accepted very gradually. Try to relate her to a niece/god daughter of a similar age and keep it very casual and relaxed - you'll get there in the end.

Don't get upset if she hates you. its not you. its just the fact that you aren't her mum.