For a woman that can't walk or even stand, which is better, an adult diaper or a pull-on such as Depends?

I might have missed this part - but does the person the poster is caring for have the ability to tell when they need toileting, and can they sit? Would a transfer to a bedside commode be more workable than incontinences products?

I would suggest adult diaper otherwise you have to remove socks shoes pants etc to get pull-up off and out fresh one on. I just learned about this recently.

I would recommend an adult diaper. Attends makes great ones that can be fastened but also are designed like a brief to make them more comfortable and protect the skin. Tena is another great brand with similar style. This particular diaper states is make changing easier, which could be helpful in your case. If mobility is an issue, you may want to consider underpads for chairs and beds, in case of leaks. There are both disposable and reusable kinds.