I've also had a stray/lost kitten turn up on my door step this morning. I've posted on Facebook, knocked round the neighbours and no one can shed any light.
I managed to get her in the car carrier to pop to the vet who thinks she's about 7 weeks old. No chip but in reasonable condition though hissing a lot.
I'm reluctant to call Cats Protection because I think she has a safe and happy place for now (though I'm not sure it could be permanent - Dennis loves the fuss of an only cat) and I would hate for her to go in a cattery.
Any advice is welcome.
Her name is Mildred