One of the first things to understand when you are thinking about when to claim Social Security is that after the death of the higher-earning spouse, the higher benefit will transfer over to the surviving spouse (her own benefit will stop) and continue to be paid for as long as she is alive.
Because the higher-earning spouse’s benefit is determined by the age at which he initially claimed his benefit, the higher-earning spouse has direct control over the amount of his spouse’s eventual survivor benefit. He can maximize that benefit by delaying the start of his benefit to age 70.