My 1st thought is its your daughter, and for you to help her, and be the bigger person...then along comes the thought of only you know how things were and are for you and your feelings regarding the past marriage and divorce... I don't have a daughter, and haven't been through a divorce...I do have a son, and my parents were divorced, so I have some experience...as it is for me, I would help my son with anything he asked me to...my feelings would be second to his. Good luck with whatever you decide. I do have to say I did get a chuckle when I read GmaJane's comment above...
Regards,
Kif