I ended up giving them all gifts (which included high end chocolates, high end spa products, candles etc.) and aside from one of them making a rude comment to one of my close friends about her missing my shower to celebrate a religious holiday, the rehearsal went by without incident.
The comment was essentially that ex-bridesmaid did not feel that said holiday was a valid reason to miss a bridal shower...

My friend simply responded that she felt that it was and moved on with her evening. My friend told me about the incident when I walked her out to say goodbye.
She was offended but also well aware that the other woman was probably just trying to start some drama.
I really think that some people are just always going to be miserable, no matter what you do. It just kind of makes you shake your head...