I agree with everyone who said stick at your current job and see if you can widen it. I work at a university and there is a lot of movement within the uni for admin posts with good candidates getting snapped up by other colleges and departments, plus you are very unlikely to be made redundant, more mopped up elsewhere if your job ends.
You have a permanent job- if you move to another job now, in whatever sector, the chances are it won't be permanent but you will be on probation and depending on the redundancy situation, may not be kept on. Jobs like 12 hours a week at a uni (so ok pay per hour) round school hours are like GOLD DUST and if you give this one up, you will have 100 other mums who want to work part-time in that field.
I would also sit down with your husband and work out finances. If you start working full-time hours, with a commute, for example, then you need to work out the cost of childcare and commuting. That will be £100's a month, I pay over £100 a month for a tiny bit of after-school care, if it was every day, I would find this a real struggle.
Basically, with a full professional wage, the childcare is worth it, with a not so great wage, you may be financially optimized in your current position.
I am not sure that you going full-time, out of your sector, even if you can secure a job is going to give you foreign holidays. You will have so many extra costs, plus possibly cleaner/issues with shopping.
I would sit him down with the exact figures of one of these jobs he thinks you should get and work it through. In his fantasy land, you take anything, you get holidays- I think the truth of the matter, unless you are reasonably high earner is probably quite different.
I would stay in the uni sector and apply internally for good jobs in the university/other nearby universities.