The spousal benefits are indeed reduced if she filed prior to her full retirement age. Per SS:
A spouse can choose to retire as early as age 62, but doing so may result in a benefit as little as 32.5 percent of the worker's primary insurance amount. A spousal benefit is reduced 25/36 of one percent for each month before normal retirement age, up to 36 months. If the number of months exceeds 36, then the benefit is further reduced 5/12 of one percent per month. You can read about it here:
https://www.ssa.gov/oact/quickcalc/spouse.html#:~:text=The%20spousal%20benefit%20can%20be,will%20receive%20a%20reduced%20benefit. You may be thinking about survivor benefits which have their own set of rules.
There are two standalone benefits involved - her own and spousal, they can be and often are claimed at different times and therefore can have different amounts of reduction (plus they are reduced using different formulas). For instance, if she is getting $800/mo on her own record only and claimed at exactly 62, her PIA would have been $800/0.7 = $1143, that reduction for early claiming is permanent.
If ex's PIA was greater twice her PIA, (so $2286), there would be a spousal benefit equal to 1/2 of the difference between his PIA and $2286. Let's pretend that ex's PIA was $2500, so she would have a spousal benefit of:
(2500-2286)/2 = $107. That benefit uses the reduction formula that you referenced for being claimed early.
The question is whether ex earned enough for there to be a spousal benefit and if so, was the spousal benefits actually claimed early. If you just call up social security and tell them you want to claim benefits, they will claim on both your own record and your spousal automatically unless you instruct them differently, so what you are thinking may be what happened, in which case, her current benefit is all she will ever get.
However, OP also said she was older than the ex and that she claimed at 62. Meaning ex would not have been eligible for benefits when she claimed, so (based on what we've been told) she could not have claimed a spousal benefit at that time. If she never did and now she is past her FRA, the spousal benefit would not have been claimed early, so that portion of her total benefit would not be reduced. You can see from my pretend example that unless ex was a high earner, the spousal benefit would be non-existent or very small, but if there is a spousal benefit and it was never claimed, there would be no reduction on it if spousal was not claimed early. But we are putting the story together from fragments, the Social Security folks are who she needs to talk to.