Hi Gem, unfortunatley education is like the NHS is differs so much depending on your postcode, nursing is a it easier to get in to than midwifery and then you can just do the MW course as a postgraduate one of the student MW when I had Freya was taking this route and had obviously been working and getting paid as a nurse while training for her MW qualification.
check out this website its very clear and easy to understand, by no means are you too old to retrain infact it is ageist for a college to not take you on based on your age (within reason!! lol) but one thing I have considered as I've thought of midwifery as a career change is the shift work, you may be away from your kids for longer than you might with a 9-5 job but there will be days when you aren't working at all (ie 5 on 5 off) and being pregnant is a hazard of the jobs for MW's with all those cute babies around!! there were 2 PG ones on shift when I was in hospital and another just had hers!! so having another baby will fit in with your plans absolutley fine Im sure, changing careers can be so scary!!
I teach adults students at our local college to be florists and we have all sorts of ages on the part time courses if you passionatley want to change career you can, its about determination and you need support, the fact you're posting about it already shows you want it!!
also the open university has a 'help' checker if you get tax credits or have a household income under a certain amount it tells you how much aid you can get with your fees
good luck Gem, heres the web addresses take care xxx
http://www.acareerchange.co.uk/changing-career-becoming-nurse.html
http://css2.open.ac.uk/FafCalculator/eligibility.aspx?OFS=False&Country=ENI