Thanks guys!

Dh is petrified of loosing her he seems to think that she will hate him he literally almost gets himself in tears about it. I try so hard to reassure him and his comeback is "she is always gonna be your daughter no matter you cant change that & neither can she but Im not her dad biologically and she might not want to call me dad anymore"

We have different views on this I believe that she asks to contact her bio dad then we should do it & he is dead against it
The contact with bio dad issue is causing friction in my family at the moment . I personally think honesty and transparency is the right way to go.

My older sister wants to get to know her bio dad's family (not him, because he died) and I really really don't. My step dad doesn't want us to either. But it would be much easier on all of us if we were just left to decide what we wanted to do and freely do that with no fear of hurting others etc.

All I can suggest, from personal experience, is the earlier she is told the better, and likely the less interested she will be in hunting him down.

Hope it goes well for you .