I'm a little confused about what you're asking. Are you thinking of asking the headteacher at your daughter's school if you can train there? I'm sure they'll bite your hand off if you are not expecting to be paid a wage, are prepared to pay for the cost of the course and pass the CRB check. What course are you thinking of doing? Level 2/Level 3 Supporting Teaching and Learning in Schools (STALIS)? Or a Children and Young People's Workforce Level 2 Certificate/Level 3 Diploma? STALIS is of course specific to schools, whereas the Certificate/Diploma allows you to work in all kinds of settings including nurseries and pre-schools (I know somebody who is doing the Diploma - ultimately she wants to train as a primary school teacher and is doing her placement in a primary school).
These qualifications will help you to get work as a teaching assistant but they are not necessary (not for secondary schools anyway, some primary schools ask for a Level 3 childcare qualification e.g. the Diploma, the BTEC National Diploma in Children's Care, Learning and Development, or the now defunct NNEB). The most important thing to have is classroom experience, and a reasonable standard of general education. Some schools ask for GCSE English and Maths, some don't, but you will struggle on the job if you don't have them.
OK, so after taking advice from you lovely ladies about retraining (as I'm having no luck finding work after 5 years out), I've decided to become a teaching assistant. Don't worry, It's not something I've not thought of before! I was offered a work based training place in Kent. I used to help out a lot in my godsons class, and his teacher and HT asked if I'd like to do it. I had wanted to train as a teacher after a levels, but had to leave early so it never happened.Was about to start and finally after 6 years of trying I got pregnant with my dd. So, I've been helping out in dds class, and it made me recall how much I wanted to do it before. Does anyone have any tips at all? I'm nervous of asking dds ht (who is lovely), but I'm getting nowhere with the skills set I have now, and 5 years, despite having my freelance work on my cv makes me unemployable.