Whether it is how to arrange the furniture in their new apartment, or how to manage the home they are leaving (which needs to be emptied, cleaned, listed and sold), I am getting pushback from my younger sister. I have masterminded most of the search for senior living for the parents, and they are needing lots of help in this area. My sister says, "I don't want to be pressured," about most things I bring up, including renter's insurance, what to involve mom and dad in on moving day, how to plan for selling the house, etc. I end up giving in on many things that I think are really necessary. My husband tells me I am a pushover for not standing my ground with her, but my dad talks to her and she says she is, "trying to make this easy for them and keep them happy." I can't stand in the middle any more. I am ready to stop doing anything and let her do all this work. I do their finances, help with healthcare decisions, change addresses and track down insurance and Medicare/Social Security issues, and negotiate with the senior living community they are entering. How do I stand up to her??
If your parents want you to just "work it out" with your sister with no input from them they're really doing all of you a disservice. You're perfectly within your rights to tell your sister she can defer to your research and wisdom or she can do it herself.
That being said, the caregiving arrangement works best when it works for both parties: care receivers and care givers. I don't think it's working in your case (although it's not as bad as it could become). If you can let us know who the PoA is and when the authority is active (springing vs. durable) it would be helpful to answer your question.
Also, are you SURE they only need IL and not AL? Your profile says your mom has dementia. What about your dad? Have they been assessed for their ADL skills and cognitive/memory levels? You don't want to move them (which is hard on seniors) only to find out they need a higher level of care within a few months. Does the IL community they are moving to have a campus of other care options, like AL, MC and LTC? This would be important to have. I know this is all hard -- been there and done that. Wishing you much success in helping them while working out unity with your siblings.
Me, I had POA for financial and Medical. One brother was 8 hrs away, the other chose to do his own thing. So I made all the decisions. I only consulted with my one brother when I needed some input. I did, with the help of DH, all the clean out. I was able to do it over a period of time, though.
I loved the way my neighbors daughter cleaned out her Moms. She had everyone come in an sticker the items they wanted first. When everyone was satisfied with what they got or compromised if 2 wanted the same item, they picked up their items and the rest was gotten rid of.