she wasn't questioned on what she had been doing for the last 5 years- it was obvious, she walked back into a teaching job. Being a SAHP had not hindered her job prospects like it would today
However there are some professions, and teaching is one, where women are very well represented. I don't think anyone would bat an eyelid at a teacher taking time out while the children were pre-school age, but maternity leave arrangements are pretty good for teachers and most of them do seem to go back. Even if they didn't, their professional qualifications would still be valid, and you could even argue that becoming a parent adds to a teacher's CV.
I think it's a different situation in other professions which aren't quite so accepting of family life, or those where shifts and weekend working can be difficult to accommodate. Obviously in all professions, it's important to do as much CPD as you can throughout, and try to maintain contacts.
I seriously doubt a teacher who had taken a career break would be discriminated against solely for that reason. I know there is quite a lot of competition for jobs in teaching now, mainly because there are so many recent graduates looking for NQT positions. At both my DD's junior and secondary schools there were/are qualified teachers doing TA jobs hoping for vacancies to come up.