I live with and care for my aunt. Is there someone who can negotiate on my behalf with her kids about finances?

I am 58 and live with my aunt who has had a stroke, she is 80. She also has children who help some but not day to day. I am the maid, chef, gardener etc. She has 7 children who are involved on different levels, some come around and are more involved than others. I cannot manage a full time job and do what is expected or needed from me. I receive "room & board", but no salary. Therefore it is very difficult for me to keep my finances current. I actually pay her a small amount of rent when I have a full time job. She insists that I pay rent so that her children will not think I am a "free-loader". REALLY? I have tried to approach this subject very diplomatically with her children. There answer is what ever mom says. I honestly know that her children have no idea at how demanding she can be. I guess my question is: Does your organization recommend or have a person that can negotiate on the behalf of the care giver?