Rules for Collecting Ss on Spouse's Record

I've got a relative who posed a question and I've been unable to find a definitive answer (short of having her go to a SS office to inquire). She is 10 years older than her husband and she began collecting SS at age 62, ten years ago. Her husband is now approaching 62 and is also thinking of starting his benefits early. If they were the same age, she would have started benefits at the same time and would have collected more under her husband's earnings record than her own, as she worked pretty much the minimal amount to qualify. The question is whether her benefit will adjust upward and switch to 1/2 his benefit or is she stuck at the lower amount because she already started under her own earning record?

SS law is not my thing, so if anyone knows, thanks.

Rules for Collecting Ss on Spouse's Record