Dd not wanting to spend time with me

[Sam983]

Have been separated from dd and ds's mum for 7 years, and on the whole we get on.
However recently my dd has been reluctant to visit, and when she has it's been with appalling attitude and bad behaviour from her. She's 10 and starting to develop, and I wonder if this is having an effect?
I've spoken to her mother about this, and she's not very supportive, although doesn't encourage dd not to come over. I have them every other weekend, which has dropped over the last 2 years from every weekend due to their commitments and outside school activities.
Anyone have words of advice? I have a decent stable home with dw and step kids

Have you asked her why?

Yes, she just says she doesn't know? Had a frank chat about it earlier, but still nothing - she's going to think about it apparently.

I'm also worried about the effect it's having on my ds, and the step kids (they get plenty of grief from their real father, no more needed for them).