Can I use mom's joint account (with her husband) to pay for her assisted living expenses even though he refuses to go?

She wants to go to assisted living, he does not. He has dementia but it's not diagnosed by the doctor therefore he says he can care for her. She will die if she goes home. Family Services was involved at one point because she was not receiving the proper rehabilitation. I have been paying their monthly expenses per her request with the same account.