Not sure what to do

When I was a child my cousin molested me.. I thankfully didn't see her much after that because her family ended up moving out west a couple provinces away. I never told either of my parents, or anyone at all for that matter. (My parents are divorced, this happened when I was visiting my dad at my grandparents campsite and her and I went to the public bathrooms. I wanted to tell him but I was too scared and didn't know how to)

Now we are adults and she's lived out west most of our lives so I've been able to avoid seeing her.

Well now, after all these years. she's coming back to visit, my dad is so excited and I just cringe at the thought of it.

I was just planning on avoiding having to see her, always being busy etc.

Then I just got an invite for a family reunion happening at my dad's while she's down for her visit. It's been a while since I've seen all my family members and I don't want to miss out on seeing everyone but I DO NOT want to see her. Do not want to talk to her. Do not want her meeting my kids and or laying a finger on my 5 week old.

I hope her stupid flight gets delayed so she can't be here. I literally want to puke.