I am not quite sure I understand Fiona...

You're feeling like you've given her lots of info etc, been very friendly and helpful & she's not giving you what you want? Is that right?

I get if that's the case that you would feel a bit bewildered and like you are banging your head on the wall.

I think you need to decide your motives for being helpful & friendly. If it's because that's how you prefer to be. Then continue to be you and let go of expectations on how she should behave.

She may never respond to you in the way you want her to & I get that's hard but that's a reality. If you're only being nice to get that back from her then you need to decide what to do now on I would say...

Remembering she has a history with your partner that you don't share. She has suffered hurt & pain that you probably could never understand. That was their history. It could be quite confronting for her to have financial issues still with your partner after all this time and the double whammy of what might feel for her as a loss of her daughter to you...

It could be a real challenge for her. As I recall your DSD had issues with her Mum and came to live with you. Now you guys are also having issues too - teenagers are hard work. Teenage daughters and their Mums are a fragile reaction at the best of times... I would hazard a guess that it's very very confronting for this woman to have her daughter gone from her life and over here...

So, if it were me personally I would behave as I feel authentic doing so. I would also give her a bit of rope as I really think there would be a fair amount of pain for her in the situation...

Being nice makes you feel good & it just might over time help your family have some healing...