So you think that people will actively exclude themselves from well paid work, so that they can take advantage of subsidised training, so that they can gain access to well paid work?
In a parallel universe where there are only two kinds of jobs, low paid and well paid, I doubt it would be an issue, no.
Back in the real world where there is a range of income levels rather than just the two extremes, yes, you can create a notable strata where it no longer makes sense to be relatively self sufficient, given that it hampers your economic and "free time related" access to education and training.
And additional issue is the risk of creating a breeding ground for resentments.
The OP would like gov funds to ease the time/responsibility restraints of being a parent that prevent her from undertaking education right now.
Another person might also like gov funds to ease the time/responsibility restraints of being employed (in an "ok but not great" paid job that they seriously do not love and really can't face another 2 decades of)...that prevent them from undertaking education right now.
Ease the burden of one, but not the other and you create enough sensation of "unequal access to opportunities" in the public which in turn supports governments that claim to be wanting to cut just the fat of the welfare state, all while they sharpen their knives ready to start hacking at the very bones of it.
It's a lot more complicated than than just the cost of X number of hours of childcare v Y being the hypothetical presumed final income of the person supported in access to education should they complete their studies and then go on to find work in that field.
The whole caboodle stands or falls on a public willingness to support a safety net above and beyond the bare minimum in cases of abject necessity.
I'm not sure the Uk can put its hand on its heart and say they managed that balance adequately, and the people on the soggiest end of an unlevel playing field will likely be the ones who end up paying the highest price of that miscalculation.
It's not even like a lack of paid for childcare has to block the OP from making a re-entry in education Right Now.
GCSE Bitsize is a good place to start placing the groundwork for future study if she is missing the required GCSEs for entry into social work. I didn't find the teaching for the required maths GCSE on my access course anything like enough given that I hadn't been that brill at maths at school and I was well rusty. Not while my poor brain was trying to cope with all the other things I had to learn (essays etc.) all at the same time. Wish bite-size had been around back then, I would have spent a whole year on it trying to get past some of my bigger "maths issues" before it mattered.
This free course from the Open University via OpenLearn is a great introduction to academic writing, which is a bit of a learning curve on an access course when you are going in cold.
Open Learn also has free access to a whole plethora of resources so the OP can examine the degree to which she is attracted to social work as an idea, or also as an academic endeavour
Again focused on improving written communication, a vital tool for university level study, especially for those of us who never got beyond compulsory education at school a course from Coursera that has already started and can be joined right now.
....and I am just quickly skimming the surface here of just a few resources. There is loads out there that the OP can access right now. She can start her journey into a better tomorrow via education tonight in a manageble self directed way that is aimed to set herself up to succeed and make later parts of the journey a little less "steep learning curve". Via resources that can help her hone and develop academic skills, gain a better understanding of the subject she intends to study before she is committed, to pique her interests in other areas that may turn out to be a better fit once she has had the change to try tastes of things that catch her eye.
All in all IMO a better re-entry into education than just funnelling her into a brick based course without giving her the chance to contribute any personal investment, time and effort wise, into exploring her capacity to develop self motivation, stickability, finding ways around the usual suspects that demand our attention away from the slog of study and creating supportive networks of people with similar interests in similar circumstances, so she already has a strategies and backup when the almost unavoidable fatigue of adult education mixed with adult responsibilities hits her.
I don't believe that just chucking money at childcare is the best choice for the OP's future study, the best use of funds, or the best way to avoid whittling away at public support for a safety net that I would prefer to see left intact enough so it can still help provide 2nd chances for those of us who don't hit the ground running the first time around, who instead fell flat on our faces at 16 (