What Should My 67-Year-Old Mother-in-Law Do With $150K?

My mother-in-law is 67, a widow, and in good health. She lives off a modest pension (~$1,200/month), that covers her rent, groceries and essentials.

I found out this weekend that she has $150K sitting in a Chase account earning a miserable 0.01%. I spoke to her about HYSA, where she can earn around 3.5% and she's open to that.

What other advice should I give her? She was a stay-at-home mom her entire life so she has no income, except that pension and the savings account. The stock market is not an option. What is a relatively safe place where she can put her money, have it work for her (i.e. make more interest than a HYSA), and have access to it relatively easily?

TL;DR: What options should my MIL consider to ensure she’s financially comfortable for the long term, if she currently has 150K in a Chase Savings account?