My mother is being abused and isolated by a sibling. What can we do to get access to her?

Adult protective services were notified by a health care agency and family. APS is saying they can't do much if mom says she is okay. Family and friends have no access to her. My sibling's spouse is also a cop. What can we do if APS is dragging their feet for the last three months now? Sibling seized control of all assets, has been removing valuables from the home, sold parents car and got mom to sign over a limited power of attorney. Mom fell at siblings home and sustained a brain injury and had to have brain surgery. No one in the family was informed. We hear mom is now bed ridden and they are telling people she has dementia. What can we do to get access to mom? Please help before it is too late. By the was sibling and spouse are both on disability with several small children at home and she unsuccessfully tried to get a restraining order issued on me when We confronted her about Mom's injuries and seizing Mom's finances and car. Please help before it is too late.