How do I change the home health agency my sister has hired to care for my mom while she has Power of Attorney?

My sister has POA for my mom since she lives in the same town as my mom. She said she needed more help with Mom since Mom still lives in her own home. She called me frantic about how tired she is and she needed a break. She told me that if one of my daughters could come live with mom they could be paid to take care of her. I asked my daughter and she said yes she would be willing to do this. She quit her job packed up a infant and moved there. She has been there since April and the only income she has seen has been what we her parents sent her until she found a job. Now my sister is complaining because my daughter works. My mom does have a lady that sits with her while my daughter works. My daughter does home health but my sister will not switch Mom over to the agency my daughter works for. Also, we noticed that all photos of familiy siblings have been removed from my moms house only my sisters family photos are there. She doesnt by any groceries for the house or pay for any of my mothers personal care items. My daughter just called me because my sister was bad mouthing her to the neighbors. My daughter was in tears. I drive there every other weekend to visit which is a 4 hour drive and my sister tells the family I never visit. My moms bank account is now empty and the last time we went to the attorney I had to pay for it. I am at my witts end with her and the family. I am the youngest girl and at the onset i wanted mon to live with me but the family said no but they want my family to do all the caregiving and paying the bills. I am so thinking of going to get my daughter and her little girl and bring them home but my mom is now attached to the baby and my daughter doestnt want to leave. Sorry for the long message but just needed to vent a little.