Who can I contact, other than the Illinois Department on Aging regarding a senior citizen I feel is being financially extorted?

I've been the POA both medical and financial for a senior citizen and friend for the past 15 years. She's had brain surgery, heart surgery, breast cancer, colon resection and many other hospitalizations during that time. Her three friends, myself, and two other ladies who are alternate POA's and two of us are also the executors of her will have been her primary care givers. In the addendum to her will she lists that she has a niece and that the niece is to be given nothing and not even allowed to attend her funeral. All these years she has told us the niece stole from her and that she has had no contact with her in any way since then. Now that my friend is 88 years old, she recently received a dementia diagnosis and her doctor sent us all letters asking us to take over her finances. When we did, we found that her electricity was going to be turned off the very next day so we quickly paid the bill. She has been in a very nice upscale skilled living facility and we have been paying for it from her account. She has quite a bit of money. She is leaving it all to various animal organizations and we are not beneficiaries of the will nor do any of us receive any financial compensation in any way.

About 8 months ago her niece who lives in Arkansas showed up here in Illinois and decided to rekindle the relationship. Now that our friend has dementia, this niece has convinced her to dissolve her medical POA and list the niece alone ad the medical POA. This niece lives in a different state and works in a restaurant. In the last 8 months we have all repeatedly tried to call the niece to let her know that her aunt was in the hospital and she will only communicate by text message. She texted that she is unable to take calls during the day because she works in a restaurant. It seems like it is pretty unsafe for her to be POA since the nursing home will be unable to contact her during the day if a medical situation arises with my friend. As of today, we are still her financial POA's as far as I know but today the niece came back into town and took my friend out of the facility and brought her to get her checkbook from us. We can only assume that our friend is now going to add her niece to her checking account and that our financial POA's will soon be a thing of the past. The problem is that this niece has told two fo the caregivers that she is flat broke in Arkansas and needs to find a place to live and wants to live with her aunt here in Illinois but when she asked our friend if she could live with her, our friend said no. Our dear friend has a dementia diagnosis. She doesn't even remember who has visited her during the day most days. We all believe this niece has suddenly appeared after 35 years to financially extort money from our friend, her aunt. Her doctor was the one who actually launched an investigation with the department of aging based on the suspicion of financial extortion. We were contacted by the ombudsman for the department on aging. He basically told us he had talked to our friend and she had refused assistance from the department on aging and so there was nothing more they could do. I emailed him her medical diagnosis and our POA's but he said it didn't matter if the person had dementia.. if they refused assistance, there was nothing the department of aging could do to help us. Is there a different organization that we could contact? This was the hotline for senior abuse we called in on to say we suspected fraud and financial extortion so that department won't help us. It's hard to believe they won't investigate when they have evidence that the person has dementia???? But anyway, if there is another organization that protects seniors I'd like to notify them. I don't really have a dog in the fight except that I am hoping that our friend doesn't end up with all her hard earned money going to someone she did not want it to go to and that she herself can stay in the nice facility we have set her up in and not end up in some cut rate place when she has plenty of money to live out her life comfortably. We all think the niece is going to take all her money and leave her destitute and unable to live in comfort. What options can anyone think of for us. Maybe we will just have to accept things as they are and just try to be friends with her no matter whether she ends up in some awful place far away and the niece takes it all. It's just hard because she trusted us all these years to protect her and now we find our hands are tied. She anticipated all this happening and tried to circumvent it but legally we really can't do a thing.