Good luck if you do go ahead.
I trained post A-levels in 1998. No kids, no Dh etc - and it was still hard work!!
However, how much research have you done already? You may be able to miss 1 year of the 5 year basic training based upon your previous experience but only certain universities offer this option. I trained at Leicester and we were affiliated with Warwick for a while that did a specialist 4 year course for graduates. Would you be prepared to move your family or are you looking at a university close to you?
In terms of the training, the graduate course is more intence, usually the first 2 years are university based and the final 2 hospital based with some overlap between the 2.
For the vast majority of the training your set hours will be roughly 9-5 with private study on top of that. And hundreds of exams! In fact so many exams that they become second nature so it isn't as sacry as it sounds.
I think the main thing for you to consider is what you want to do post medical school? You're probably aware that the whole system is one big sorry mess at the moment but it won't affect you as in 5-6 years time it should have sorted itself out (fingers crossed!)
In my personal experince certain specialtities are better suited to having children. Sadly my original chosen speciality (surgery) wasn't one of those so I'm probably better discribed as a resting doctor these days until our family is a little older!
I could rabbit on all day. so I'll sign off but happy to answer any more questions for you if you have any.
Oh I should say that in my particular year there were several mature students , 3 of whom had children - but they were all men