Is it rude to decline baby shower by ex mother in law??

I’m pregnant and I decided to leave my baby’s father (toxic, narcissistic). We haven’t spoken to each other or seen each other in almost 2 months and probably won’t until baby is born. His mother wants to throw me a baby shower... I don’t know anyone here in Orlando as I’ve only lived here a short time and most of the people invited will be his family and friends. Would it be rude to decline a baby shower??

I don’t feel like putting on a fake smile, or pretend around people I don’t know.