If your permits entitles you do National Health care provision, if you girlfriend is using a pump, this should be funded by the PCT where you choose to live..
It is likely that there will be a delay between getting here and when funding is granted (some PCT's will try to make this delay as long as possible given half the chance)
When you arrive, she will need to register with your local GP who can refer her to the hospital diabetic clinic so that the funding process can begin it will be the consultant who makes the application to the PCT for funding..
She will need to bring as much pump supplies as possible to tide her over while waiting for funding, as for insulin and BG test strips, this side will be dealt with by the GP surgery, and should be set up for repeat prescriptions when you register...
She will also need to contact her swiss pump manufacturer, as they will be able to provide all the neccesary information for their UK office/supplies in case she needs pump support or order supplies before the funding side of things kick in...
Another consideration, what Blood Glucose measurements does her meter (and pump if it's got carb/bg wizard) use, mmol/m's or mg/dl? As she would need to check whether the BG test strip works in either pre-set meter, and how this reflects with her pump etc.. Worth double checking with the manufactuers concerning Test strips readings etc...
I couldn't say what permits/Visa's that entitle an individual to National Health care, but I suspect either you already know this part, if not the swiss British Embassy should be able to help clearify this side of things...