Hi Ian
Welcome to Rootschat

We have a 'no living people' policy here so please don't mention the names of who you are looking for.
And the information we give can only be generalised. Despite the popularity of some television programes, not all adopted families want to be reunited.
The family may not appear on the online versions of the 'edited' electoral registers as you can now opt out. Is the fact you can't find them on the registers making you think they have emigrated or do you have other evidence.
Have you written to the new owners of the house to let them know you plan to visit or are you turning up out of the blue?
Have you also tried finding out if she had any brothers and sisters who may be able to forward a letter on to her?
I'm sure other chatters will join in and once you get to a post count of 3, you could send and receive personal messages.
Dawn