Molly - it depends really. If you worked shifts etc, you might not need full time childcare. In fact, in all my years of low paid jobs, I think one was a 9-5 job. Care homes, shops, call centres, factories etc, are not 9-5.
I'm just saying that this idea that people on benefits are somehow better off than people who work is not always true. You get childcare tax credits as long as both of you work at least 16 hours (they are changing it now so that one of you needs to work at least 25, and the other 16) so you could get childcare mostly covered with just part time work. Obviously this depends on there being jobs to get, but that isn't the discussion.
In fact, my husband works part time (the only job he can find) and I am disabled, and if I was able to start part time work I think we would still get pretty much the same benefits, maybe a slight reduction in council tax benefit so we would have to start paying some of it, but nothing so that we would lose out on a lot of money overall. We already get childcare tax credits as I am too ill to watch the kids full time, and my DLA would actually mean we would start getting disabled working tax credit if I worked. We certainly wouldn't be on a luxury income, but we would be better off.
One of the founding principles of the welfare state was that of "less eligibility" ie that somebody working should be better off than if they weren't. Obviously there are exceptions, there always is, but in general, I would say that is the case. IME, people who find themselves worse off by working tend to have not claimed what in work benefits they could, which is up to them.