Nope, they won't ever catch up.
If you assume, say, a 5% annual pay rise, and that the woman was earning £25,000 when she took five years out, when she comes back, a colleague who had been at the same level will now be earning almost £32,000, and she would be very lucky to be able to get a job paying £25,000, as her skills are five years out of date.
That ignores the likelihood that her colleague will actually have moved to a more senior position elsewhere.
If the woman has a partner, at the end of the five year career break, he will probably be earning more than her - so his career will take precedence when deciding where to live, who will take time off work for caring duties, who will be able to travel for work, who can commute.... So she gets stuck on a different track, one where she has more balls to juggle, and gets less recognition for it.