Bed Pads Washable Waterproof, Queen (60" x 36", Pack of 1) Incontinence Bed Pads & Pee Pads, Perfect for Kids, Adults and Elderly

I use these on my dad's bed. Washable, they tuck in all the way under the mattress, no way she is not going to pull this off. and you can toss it in the washer. I keep one to put on the bed and one in the washer, And it goes on top of the sheets. https://www.amazon.com/SOLOSHINE-Washable-Waterproof-Incontinence-Perfect/dp/B0CX58VLS6