I feel really mean about this, but there is a good reason.
We had a big family party about 6 weeks ago, which ended in a fight between 2 members of my family. The instigator of this fight was my 23 year old cousin. I stood up to try to stop the fight (simply because I was nearest) and my cousin shoved me so hard that I went flying and ended up on the floor. He's a big bloke, I'm 5 foot 2. He told me to stop whinging when I asked him for an apology. He and his sister and his dad then continued to cause trouble for about half an hour, being rude and disrespectful to lots of people, including my elderly grandad.
It is my son's 3rd birthday in a few weeks, and we're having a party at a playbarn. My cousin has a 5 year old daughter, but we haven't spoken to them since, and I do not want to make contact until I get an apology. If I don't invite her, she will be the only child in the family not there. There is no one willing to mediate, so if I invite her, I have to accept that her dad will bring her.
On the other hand, I do not want to spite the child.
Any advice would be greatly appreciated!