Too little information. I could dig through the Site Search, but I won't on this occasion.

I think I'm terrible at playing politics, so take this with a grain of salt:

If you don't see your daughter on many special occasions, then you should accept. If you get the impression that she needs to have the opportunity to talk with you, alone, and wants to do it on a special occasion, then you should accept. If you talk with her regularly and see her regularly and get the impression that there is family politics involved in her invitation that will put you in a bad situation with the rest of your children and step-children (and wife) with little benefit to/with her, then you should either beg off and reschedule, or try to make it a family gathering at a neutral location.

In short, I think your choice depends on your relationship with your daughter. I hope you made the right choice! :-)

Cheers,
Scott.