Can a sibling who has POA keep another sibling, who cared for the Mom for 2 years in her home, from seeing their very ill Mom?

The police must have seen obvious circumstances that led them to remove the mother from the home, from her "favorite" daughter (by your determination?).

Police removal of a person would not be considered kidnapping by 5 siblings. It would a removal for legitimate reasons such as neglect, financial exploitation, inadequate care or abuse.

There's more going on to this situation than 5 adult children "kidnapping" their mother.

We can give you better answers if the whole story was known, as obviously there's family friction and a difference of opinion as to what's right for the mother.

If the mom was truly "kidnapped", why would the police help the family kidnap her?

Technically POA doesn't have anything to do with family dynamics but more often than not someone with POA will run around waving the POA claiming "I have POA!" and expecting things to be done their way. This is fairly common.

If the daughter in this scenario would like to see her mother I would suggest that she approach the sibling who placed mom in a nursing home and politely ask to see her mom. If this is truly about being able to see mom.

Or the daughter from whom the mom was taken can hire a lawyer and try to obtain guardianship over mom. But if there are 5 siblings who are all fighting over mom the only people who are going to win in this situation are the lawyers.

If five grown children felt that their mother needed another layer of care that only a nursing home could provide, then there had to be a really good reason.

There is apparently a back story to this situation.