Can I fire my mom's attorney that shares "financial POA" with me?

Weird question I know but so is my situation...my mom was finally diagnosed w dementia 2 days ago. After years of asking for help, writing letters to her attorney & doctor and several conversations, it actually took an ER visit and trip to another hospital. Mom has a mass on pancreas and now has pancreatic cancer. However, while she was there her actions and state of mind was much worse than ever and it didn't take long for a good doctor to diagnose her w frontal-lobe dementia ( I believe that's it). When I called the attorney's office to let them know, I asked if I could have them put some of the 5,500.00 they collected for house pymnts, into mom's account if needed so I could make final arrangements? I was informed that they had some things to finalize as well! I handle all her bills, etc and the attorney does nothing! He underhandedly got on with me as POA, the ONLY time I didn't go with mom to see him! I can only imagine that he is going to present a bill for most of that money for handling her affairs? Mom tried to get the money a couple times before she got sick and they couldn't give her a check for one reason or another. And she has asked what she owes him as recently as 2 mo ago and the answer was always ...nothing! So if he hands her a final bill when she tries to collect her money again, can I fire him since he will be paid in full?