Well, she has been struggling along since my father died, so I think having a little extra would be nice. Maybe $3800 a month total plus a little traveling (she has barely been anywhere at all).
Ok - that's one piece. In addition to her SS you estimate she needs another ~$1300/mo ($15,600/yr). Does that include her mortgage (i.e. will that go down further once the mortgage is gone?)
What is her tolerance for risk? Will she get anxious everytime the market dips? Or is she more steady?
Honestly, with $525,000 in cash and at age 69 she can choose to be very conservative (protecting principle) and have a large percentage of bonds, or if she wants to 'leave a legacy' to her children or some other charity she could certainly put a lot more in equities (like a low-cost index fund) and still never worry about running out of money. Currently she's at a 2.9% WR
For example, if she put 20% in bonds (fairly aggressive) she'd still have 6 years, 8 months of living expenses in 'low-risk' assets
Or: she could put 60% into bonds (protect principle) and she'd have a full 20 years living expenses in bonds.
have you talked to her and gotten a feel about what she wants? For some people their biggest worry is protecting what they have and not running out of money. For others it's leaving something to their heirs or their community.