Guess she's mad at me, oh well

Just a vent about my Momzilla friend. Today is her second baby's shower which I am not attending as it's my cousins wedding. When my friend got married (she was also a bridezilla), I missed the same cousin's 21st birthday because I was a bridesmaid and I committed to that before zi knew the date. Anyway, I RSVPed to my cousins wedding and the ba y shower without paying too much attention to the dates. When I saw mistake I messaged my friend and asked her if I could come see her in the morning rather. She said that would be fine and we'll arrange an actual time closer to the date. I messaged her to confirm and all of a sudden she has to do 'urgent shopping'. Her other friend is throwing the shower so I don't know what urgent shopping she needs to do. This friend has come to visit me twice in 10 years, I always go to her. I was there at her wedding, her first child's baby shower plus first birthday. I don't think it's too much to ask for a bit of understanding. I messaged her back to say no worries, she must let me know when she's available and again, I'm really sorry. She didn't even reply to that message.