J, you were invited, you are going to support her - leave it at that. Don't engage with your ex on any level apart from civil.
This was your choice to go and up to you to not engage or instigate drama.
What is your reason for going?
I'm real good friends with daughter and she really wants me to come. even more then her mom. I'm just going to support and celebrate with her. She was not going to invite her mom. she told me last night she decide to invite her. I figure my ex will treatment like she has been ,which is that I'm not there even though I was standing in front of her. My ex has never really fought with me. I'm more worried that she will fight with her sister or other family members. I don't plan to engaging my ex.