You better head this off at the pass. An annuity for a sick old woman is a terrible idea. She may die next year and that will be the end of the 40k. Call him up and put him on notice not to invest that money.
Call the issuing corporation and demand the money back.
My mother did that same foolish thing in Nevada. She was 83 at the time. It was being sold by a guy at a desk in the bank so she thought it was word from the mountain. Then she was afraid to tell me.
I went to the bank, spoke to the manager, made calls and wrote letters. The 40k came back but I was still angry because she lost interest for the 2 months. After that I took over her financial affairs. She gets a checkbook with 1k in it and I pay all the rest of her bills. No credit cards!