Can a POA who lives out of state pay a sibling to handle parents finances due to dementia?

I live near my parents and the POA lives out of state. Parents have been considered incapable of handling their finances so I had to step into a HUGE mess as they almost lost their home to foreclosure and didn't have care insurance either. I have been in close touch with the POA and she is very pleased of what I am doing and encourages me. She even wrote a letter giving me permission to act on her behalf and notarized. I want to know if its possible to be paid some sort of salary for what I do for them? I have actively been taking care of their finances since February of this year. I do not work and it would be nice to get some sort of income for my time helping them and is it retroactive? I have no idea of hourly salary either. I live in Washington State.