Drunk Babysitter

My mom is an alcoholic. I thought she finally stoped drinking for good since she's been told she has heart failure and a multitude of other diseases. She's been watching my 7 months old daughter for the 5 hours a day that my husband and I are both at work. Today I can tell she's been drinking although she's not totally wasted. I don't have anyone else to watch my baby. If I call in to work I'll get In trouble. My husband will be upset with me if I loose my job. I only make $1500 a month at my job after taxes so I feel like I can hustle and make that if I quit so I can care for her. Idk. What would you do?