Needing Advice

I’ve been working for a nursing home for 5 years now and the only time I’ve ever gotten written up was during my first year and I got in trouble for something I didn’t even do. Fast forward to my boss retired and we have this new one. She worked the front desk where she signed people in and that was it. She is friends with all the higher ups and somehow beat two very qualified and already trained people who also applied for head of house keeping. I do miss to much work I admit that (never had I got in trouble for missed days since) but I also now just had a baby 4 months ago and now I’m back at work. I’ve had to miss a couple of days due to my child being very sick. She got to where she wasn’t eating and kept crying to where I was up all night and couldn’t be to work due to being awake already for 24hours. Had I worked I’d be up for 36 hours (I work 12 hour shifts on the weekend) and being a first time mom I couldn’t be at work. The reason I need advice is, I’m not the only one who misses and there are people who are consistently late and or riding the clock. She has given them verbal warning and write ups but with me she never had me sign a verbal or wrote me up just sent me straight on to a 90 day probation where if I miss and it’s unexcused I am to be terminated. I was also told my child’s drs notes are not a reliable excuse. Is this normal? What do I do. (This is my first time doing Reddit) also my work ethic is very good. I’m fully trained in laundry and house keeping. I’m engaged in activities and all the residents who still have their minds know me and love me. I love the residents and people there. When I work there I’m cleaning for them bc they can’t do it for themselves so I make sure the job is complete. (I’m also from Arkansas).