Of the $40k of expenses, how much is rent?
Assuming she continues to rent, that rent is included in the $40k and her investments earn an amount equal to inflation or better, then I think she is fine.
If she retires today. in the next 3.5 years (58.5 to 62) she'll use $40k a year or $140k
In the following 4 years (62 to 66) will use $28.2k a year ($40k - $11.8 SS benefit on her own record) or $113k
From age 66 on, she'll need $9.3k a year ($40k - $30.7 survivor SS benefit)... assuming a 3.5% WR that would be $265k
Total she needs is $518k and she has $730k so I think she should be all set.
If she spends $150k on a home then she'll only have $580k and should still be ok because presumably her "need" will be lower because she will not be paying rent but would be paying property taxes, insurance, HOA fees, etc but those should be lower than her rent and that is where the rent or own analysis comes in.
What I think might be interesting is to run Firecalc with a rent scenario and an own scenario and see how different it is.
If something cannot endure laughter.... it cannot endure.
Patience is the art of concealing your impatience.