My senior is starting to go to the bathroom in her depends not just pee. Any advice?

You have no info on Senior. Does she have Dementia/ALZ? If so, she may not realize she is even going. I would suggest taking her to the toilet every couple of hours allowing her to sit for a while. Is it the same time everyday. Like after she eats. If so, get used to putting her on the toilet that time everyday. Otherwise, she is now fully incontinent and you will have to change and clean her up.

I would advise changing them. ;)

Advice about what?