I think even if you did get her into France, you will find very few campsites who will accept either Staffie or Pitbull breeds. My sister-in-law traveled Brittany Ferries once taking their Rottie and at the terminal check in staff insisted she was muzzled and advised that she stay that way for the whole stay in France. They couldn't book campsites either and were refused admittance at two aires. They didn't take her again, said it wasn't worth the hassle and she hated the muzzle. It's strange though that 'Pitbull' is on her passport as this is a banned breed in UK too, whereas Staffies are not. I do love bull terries and think they get unfair press and suffer from a bad image due to bad ownership. I volunteer with animal rescue and rehabilitation and see lots of Staffies, all darlings.
Incidentally, we have traveled with 3 or 4 dogs to France since the Pet Passport scheme was introduced. We have the dogs pictures on their passports (although this is not a requirement,) but to be honest we could walk into the Eurotunnel check in area at Calais each year with 4 Yaks on leads for all the attention they pay the dogs, they even hand us the scanner to scan them - it's all about the paperwork, and the money of course - £15 per dog each way I agree is a bit steep.