Ah, Got it.
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I firmly believe that seniors should invest their money to the extent of their knowledge and ability. As we know one's ability to think through a situation may decline in the final 10 years of life, so not pushing the investing knowledge boundaries now is important for future.
So, some seniors who were active, informed investors in their younger days may be fine self-managing, or hiring someone to manage their funds for them, and understand the basics to know when good decisions are being made and when to restrain the advisor. For them, investing funds may work well.
Unfortunately, based on what the OP indicated, this is not his MOM's situation, and I think she would be best suited to a conservative fixed income investment or even guaranteed financial income plan, that is targeted to her single monthly expenses needs (which may include a whole home, or not, now that she is single and aging). Guaranteed plans include the reverse mortgage and annuities, or a monthly spend down of a fixed income fund.
As a relative / child, it is our responsibility to look ahead and identify if MOM needs help deciding to change living situation to something better suited, if it will likely need to change due to health in the next few years. This is often a blind spot as we age.
BUT I don't think that kids investing parents money (when parents have little money saavy to even keep track of what is happening) is ever a good idea, parents deserve as much self control / choices as they are capable of, including over their own money while their wits are with them.