How do I take over my mother’s estate in order to protect her from being taken advantage of?

She'll need to give you Power Of Attorney for financial affairs. While you are at it, ask her to give you a health directive/POA for her health decisions. The sooner the better.
Good luck,
Carol

Your Mother has to be of sound mind and appoint you or anyone of her choosing to have her PoA. For now, she can add you as a "signer" on her bank accounts. You can then pay her bills and keep track of her accounts online.
If she has many assets, you may want to consider a living trust and have you appointed trustee. You then become the person who makes financial decisions for her.
good luck