Firstly I am really angry so may not be the best idea venting here but I will anyway.
I have a 6 week old DD and tonight I let her sleep upstairs with her grandma. Me and DP were in the room below. I heard DD crying and felt there was something wrong but didn't want to interfere so left her for 5-10 mins max. I then went upstairs with DP to find MIL fast asleep with DD next to her screaming. I didn't say anything to her but she acted like she had done nothing wrong and said 'just dropped off'. I'm so angry but basically AIBU to never allow DD to stay with her again at least not until she's older.