NOT financial BTW - my sister is considerably richer than me.
However, she only contacts me when she wants a favour.
This week's example. Missed my DC's birthday - no card, no text.
Texts me this morning. "think I missed DC's birthday. Anyway would like to talk to your DH about XYZ (a matter in which DH has professional experience). Can your DH ring us tomorrow?"
We have never met my sister's husband, and were not invited to the wedding, although our other sibling was. Sister has never been to the house we've lived in for almost a decade. Admittedly we are 200miles away, but have visited her probably every other year.
DH has no intention of talking to this bloke, and I don't blame him. But equally I have no appetite for a row. I don't really know where the AIBU is in this one, but my sister has pissed me off before 9 o'clock, which IMO is a hanging offence in its own right.