Acquaintance upset she won't be invited

I received a FB message today from a girl I was friends with in college 10 years ago. I was in her wedding but have only seen her once since. We haven't seen each other or talked on the phone in 8 years. We are fb friends but that's it. no drama. Just drifted apart. She found out from a mutual friend that my shower is in a few weeks, and wrote me to tell me how hurt she is that I didn't invite her. I politely responded that we are keeping our wedding small and only inviting immediate family and a few friends, and because we haven't spoken in 8 years, I didn't feel close to her anymore and therefore didn't invite her to my shower or wedding. I was direct and short with my response. She responded with a long email all about her " feelings" I didn't respond. I'm sorry she is upset, but honestly, we have no relationship. We don't send Christmas cards, emails, texts nothing, so I'm very surprised that I crushed her this much. She said in her email that she had me in her wedding so she expected to be at least invited to mine. Oh well. Im not budging.