[Esel Mann]

Per your post, your constraints are: maximum stability and maximum interest. However I get the sense (from the rest of your post) that you (or your mom) desires stock market like returns but with interest. Not gonna happen (satisfying both constraints) at this time. Sorry.

Maximum stability infers insured, as in FDIC insured or treasury insured (if you can call it or trust it as that). Maximum interest, with maximum stability infers a CD. Perhaps a TIPS? Hence shop for the best CD. TIPS are what they are. If you are willing to tolerate some risk, but still desire interest, consider micro-loans. Again there is higher risk.

Taking that micro loan (and higher risk) one step further is as some have suggested, loaning it to family. Here you need to consider the paradox: (a) fundamental rule of life: money and family don't mix , (b) for risk assessment who would one know better than family.

I feel your dilemma. I am in a similar situation with in law parents. Unfortunately with the current economic landscape stable/safe interest ain't going anywhere for the foreseeable future. It's one of the downsides to shall we say certain directions taken for the "recovery".