iPhone 14 unable to send messages to one specific contact

Hello. The last 2 days, I cannot message my MIL through my iPhone. It goes to send the text, but stops and wont send it. I've tried lots of things, deleting the thread, making a new contact, turning off iMessage for 10 seconds, etc. I can message her through my laptop, but not my iPhone which I always have with me. I have an iPhone 14. She seems to be the only contact I cannot message (and she can message me, it just goes to my laptop)