agent Mark Lyall (IRS) also says he is part of the Bill Gates foundation as a pastor, and is going to marry my Mother in law scam

This is my MIL and she is 83 years old, She thinks he will marry her and I took screenshots of her messaging. She has taken out equity of her home, gave him her SS#, he created an account with ID.me and gave her a password. She now thinks she is getting a 700,000 grant and buying credit cards and sending pics. We discovered she has most likely lost about 80,000 over last 7 years. She IS declining in memory but not quite that bad but super gullible and friends and banker have pleaded with her to stop. We just found out last year, and we thought she stopped. Her son has durable POA.She resides in Tennessee