Doesn't matter if that higher earner waits till his/her FRA for spousal benefit. Gets 1/2 the spouse's FRA benefit regardless between their FRA & age 70 or whenever after FRA the higher earner starts taking their own increased SS benefit.
"Even if he or she has never worked under Social Security, your spouse may be able to get benefits if he or she is at least 62 years of age and you are receiving or eligible for retirement or disability benefits."
Retirement Planner: Benefits For Your Spouse
To get spousal benefits, the other spouse must be receiving benefits or have applied and suspended. This makes it more difficult if the younger spouse is the bigger earner.