How to get out of going to a baby shower?

So a family member, who I know dislikes me, is getting married.  
I don't care much for her either. But her immediate family is throwing a shower and I'm invited. Ofc I'll send a gift but I do not want to go. I don't really like her prissy attitude and spoiled behaviour. 
If I went, I would literally be sitting by myself. 
How do I get out of going ? I need really good excuses. 
And no this has nothing to do with jealousy or anything. I truly just don't like her as a person and I've tried.