How awful for you
A couple of things, do you mean 'Bishops Stortford (rather than Stratford)?
When you say "I live in Germany now so cant look after her again
" do you mean that you couldn't look FOR her again (due to being back in Germany) rather than you can't look AFTER her (ie you are not able to keep her if she is found)? Sorry, I appreciate that English isn't your first language but the two mean different things
Are your chip details up to date with the microchip company so if she is found and scanned can they contact you.
I would advise the local rescues - Cats Protection (CP), RSPCA and independent ones that she is missing in their area so if she is found they will be aware of her. If it's Bishops Stortford that is in Hertfordshire and here is a list of rescues in that area - http://www.catchat.org/adoption/herts.html
I really hope she is found safe and well