Here goes my $0.02.

Your mom may live another 20 years, then you must take into account inflation. At 3-4%, in 20 years your money is worth about half that it is now. Therefore, a significant amount needs to be in stocks.

If you took 5 years living expenses (including the trips), that would be $18,780. I'd put that into CDs or MMF. The rest I'd place in an S&P 500 index which would give you growth enough to cover inflation and hopefully as time goes by a little yearly raise.

JLC