Getting Mom to sit on toilet, time for a change?

My Mom lives with me, she doesnt walk or talk, is incontinent. I puree her foods and thicken her drinks. She really hasnt changed much, it been like in 4-5 years out of the almost 8 years she has been here. One thing I have done it get mom on a schedule and she will poop on the toilet instead of a diaper. Although she cannot understand, I am trained to see the signs and also give her miralax, etc.
My problem is this...I lift mom into her wheelchair, feed her 2 hours, and then we are off to the bathroom. I lift her on the toilet and she straightens out her legs, a lot, slides down, leans over, etc. I am trying so hard to wash her poop up and hold her up at the same time. By the time I am done and I lift her back to her wheelchair I am sweating and exhausted. I do pay someone for week mornings and she is great but weekends are a killer with no help. I am burning out bigtime.
If I let her go in her diaper, it goes into her vagina, etc and is horrible to keep her turned in bed to clean it all up too. Help! What do you at home caregivers do????????????????????????????????????????
I think I will post this in another section also, not sure where to post it.