There are two possibilities:
The first is that she committed a single continuous offence. That is, she exceed the speed limit once, remained above that limit, and was caught by two cameras during that single transgression. That is obviously not applicable here as it was the same camera.
The second is that she committed two separate offences but they were committed “on the same occasion.” When a driver is convicted in that way, two fines and endorsements are imposed, but only one lot of points (for the most serious).
“On the same occasion” is not defined and it would be for a court to decide the issue if it was claimed. Twenty minutes apart would seem a bit of a stretch to meet that definition. However, since it seems one of the offences will take her to 12 points she will have the matter dealt with in court anyway and it will cost her nothing to make that argument.
Has she taken a speed awareness course in the las three years?