Hi, Welcome!
I don't think you are going to like the answer but...
The pet must be (and in this order)
1) Microchipped
2) Vaccinated against Rabies (Even if they have been vaccinated already.. this must happen
again after the microchip is implanted)
3) Around 20-30 days after Vaccination, Blood Draw for Titre Antibody Level
That blood is then sent to an approved lab, if it comes back with an approved level of
antibody then... the animal can leave six months from the date of the blood draw.
So really if you start the process today the earliest would be at least seven months from now.
However if you start the process now.. and have family or friends that can keep your pet then on an approved route the animal can be sent to you after the six month wait is over. As long as you choose a route that does not require the pet/owner to travel together. For example DH and I are going from Chicago-Manchester and on that route I must be on the plane with my cats. You would need to verify the route here:
http://www.defra.gov.uk/animalh/quarantine/pets/pdf/noneu-air.pdfIf you do choose to send her over later just make sure that she is with a friend or family member that you trust to complete the last minute required details such as the tick/tapeworm and getting the APHIS 7001 form, etc... These are done 48-24 hours prior to the flight and would need to be completed by somebody that can pay very close attention to detail.

I hope this helped... Probably not what you were wanting to see but they are pretty strict on this process.