A friend of mine is 74 and started drawing SS at age 70. His wife is 68, and hasn't drawn SS -- she worked as a teacher and is drawing STRS (State Teacher's Retirement System) which is non-SS covered employment. Has a very small SS entitlement which would probably be wiped out by her teacher's pension.
Would she still be able to claim spousal SS on her husband? Or would that also be reduced by her non-covered pension. Her husband's a doctor and is collecting at or near the maximum rate. I understand her spousal entitlement would be based on his age 66 entitlement.
It sounds like you have things a bit backward. If your friend's wife has at least 40 quarters of Social Security covered work she can draw Social Security retirement benefits regardless of what other pensions she receives. It's true that she'd likely get a lower benefit rate due to the Windfall Elimination Provision (WEP) since she's getting a pension based on her work that was exempt from Social Security taxes, but WEP never reduces a person's benefit amount to zero (https://www.ssa.gov/pubs/EN-05-10045.pdf). And, if she waits until age 70 to claim her Social Security retirement benefits her benefit rate will grow until then as a result of delayed retirement credits (DRC).
On the other hand, Social Security spousal, and widow's, benefits can be entirely wiped out by the Government Pension Offset (GPO) provision. Since your friend's wife is drawing a pension based on her work for a government entity and since she didn't pay Social Security taxes on those earnings, any spousal benefits for which she would otherwise qualify would almost certainly be offset by 2/3rds of the amount of her STRS pension (https://www.ssa.gov/pubs/EN-05-10007.pdf). So, if her STRS pension is at least one and one-half times the amount of her potential spousal benefit rate, the spousal benefit amount payable would be reduced to zero.
If your friend's wife's spousal benefit would not be fully offset by her STRS pension, then her best strategy might be to file for spousal benefits ASAP and then file for her own Social Security retirement benefits at age 70 if her own rate is higher than the spousal amount payable. She would have that option since she was born prior to January 2 1954 and she's already reached FRA. Your friend's wife should strongly consider using our software (https://maximizemysocialsecurity.com/purchase) to compare her options so that she can choose the best possible filing strategy.