Ex Secondary Teacher 'converting' to Preschool!

[IreadthereforeIam]

I've posted this in returning to work, as well, but thought someone here might be able to help!

I'd like some advice, really. I left my teaching job (MFL) when I went on Maternity leave with my ds1 (7 years ago). I have recently got a job in a local preschool (where I've done a lot of voluntary work in the past) - just bank work for the moment, but with the possibility of more hours from September when my youngest starts at school full time.

I would like to be properly qualified to teach in this kind of setting, perhaps with a mind to moving into Primary school within the next 5 years or so (when my ds's are more established in school, and my ds1 - who is disabled- is a bit more self-sufficient!!).

So what I'd like to know, is what kind of qualifications do I need? I have a BA (Hons) in German, a PGCE (Secondary school), but I think I'll probably need to do some sort of conversion course.

Thanks for any help!