How can I find mom retirement benefits to help pay for her care?

I would assume Mom is on Social Security. She would have had to work 4O quarters (or 10 yrs) to get it. If husband has passed and he made more than her, she gets his SS and if she had been receiving SS hers drops off. If Mom has assets, like investments, bonds, IRS and insurance policies, they will need to be cashed in for her care. Medicaid can be applied for but all assets have to be liquidated first. If a house is involved she will need to have that up for sale. You don't mention a husband. What I posted changes when a spouse is involved that is still living in the house. You need to speak to the Social Worker at the facility. How Mom was to pay should have been discussed by now. If she is paying privately, and her husband was in the service during wartime she maybe able to get Aids and Attendance thru the VA. But, this is a long process and can't be used if on Medicaid. She should have been made aware of any pensions she was entitled to at the time she signed up with SS. You can always ask them. Hope you have financial and medical POA for Mom. Otherwise, you cannot legally do anything for her unless you have guardianship.

Do you mean that you need to gain access to her retirement and bank accounts?

Can she understand the concept of asking you to do business on her behalf? You maybe be able to have her grant you power of attorney, but don't delay.