Should I feel obligated to attend because we are related?

by Mainer Doesn't Want to Ride the Waves
(Maine)

My cousin is hosting a baby shower for her daughter in law this summer. My initial feeling was to not attend. I actually was shocked that I was invited due to the family dynamics & past history. Here is my shortest version of our history. 1 - The cousin/host of the baby shower was my mother's flower girl as a child. When I hosted a 50th Anniversary for my parents, this cousin/host never RSVP'd or attended. 2 - The daughter in law never RSVP'd or attended either. 3 - The daughter in law & her husband has numerous times not paid for services rendered from my business, which resulted in my having to write off the debt. So all in all, I feel that this family has been very rude to me in the past and I am not really "happy" to attend. My mother thinks that I should just "suck it up" and go. I would love to hear your opinion.