If she has repaid and this was long time ago I wouldn't worry. Perhaps she can give them a call and check with the pre-employment screening company if they would like her to include it? Considering that it is irrelevant to her role, the future employer is not going to withdraw the offer of employment unless she is dishonest about the whole issue.
Posting on behalf of a friend who isn't a MNer for some advice:
Friend has secured a job offer from large financial services provider. Position is for customer service based job. In the offer pack there is a screening process bundle, in which it asks if you have ever had a CCJ.
Friend had one more than a decade ago - all paid off and long dropped off official records and credit file etc. Friend is unsure as to whether to put this on or not as she is paranoid about prejudicing her chances of getting the job (she really wants it!), and is unsure if this would be being too honest for her own good IYSWIM? The job is customer service based and doesn't involve money handling or accounts etc.
Advice please? Friend is NOT trying to mislead, but as CCJ was so long ago (so much so that she has no paperwork for it anymore and there are no records left as the court dispose of them after 6 yrs apparently) that she can't even remember the ins and outs for it, other than she had one.