My mother-in-law is presently 70 yrs old. She started her SS benefits when she was 62. Shortly thereafter, her husband died and she "switched" over to his higher survivor benefit...but technically, I think she maintained her own benefit and applied for window's benefits, which was the difference between her deceased husband's higher benefit and her current benefit.
Could she have "suspended" her benefit back when her husband died, taken 100% of his benefit, and later "restarted" her own benefit at her age 70 if by then it had increased to an amount that exceeds her deceased husband's current survivor benefit?

Hi,

No. Your mother-in-law could have suspended her own benefits at her full retirement age (FRA) or later, but even if she had suspended her benefits prior to April 30 2016 she could only have been paid the difference between her own benefit rate and her higher widow's rate. And, if she suspended her own benefits after April 29 2016 she couldn't have been paid widow's benefits, either (https://www.ssa.gov/planners/retire/suspendfaq.html).

Once you start drawing your own Social Security retirement benefits, that becomes your primary benefit for life. If you subsequently qualify for another type of benefit (e.g. spousal, survivor), the other benefit could only be paid as a secondary benefit. Thus, you could then receive a combined benefit rate equal to the sum of your own benefit rate plus the difference between your own rate and the higher secondary benefit rate. It sounds like this is what happened in your mother-in-law's case.

If your mother-in-law's husband died within 12 months of when she started drawing her retirement benefits, she could have withdrawn her application for retirement benefits. In that case she could have potentially collected widow's benefits until age 70 and then switched to her own record if her own rate was higher than her widow's rate, but she would have had to repay all of the retirement benefits she had received prior to the date of her husband's death (https://www.ssa.gov/planners/retire/withdrawal.html).

Best, Jerry