Any advice on restricted visitors during short term AL stay?

My spouse & I are going on a 2nd honeymoon so I am in process of finding an AL for mom, to take care of her for about 2 wks. Things are not good between my sibs and me. They are very jealous that mom has me as her DPOA. I am anxious that they will visit her in the AL while we are away on our 2nd honeymoon, and persuade her to change her POA, and Will, or to give them money. In the past she has too easily given them money, jewelry, keys to her house and allowed them to drive her to her bank, where she withdraws $200 or $500 cash and gives away to them. I just don't want any of that happening while I am away. My question is, can I ask the AL to prohibit visitors? I don't currently have a doctor saying she is incapacitated, should I get that evaluation taken, before we leave? Because then she would not be able to change her POA or Will. I feel like I'm walking a tightrope, between letting her live her life as she wishes and being too overprotective. But isn't this what a DPOA is supposed to do, be almost "overprotective? Appreciate any and all viewpoints.