stripy Poor girl, have you tried giving her a cold teether before feeds? it can help if the action of feeding is making her little swollen gums sore. Also you can get clove oil, put a few drops into a couple of table spoons of olive oil (or similar) and either rub it onto gums or put in on a corner of a tea towel and freeze it.
I have tried the first thing but not the second as Ava had finished teething (temporarily) when I found out about it.
Homeopathic teething powders are good, Either Nelsons or Boots, which is the same but cheaper!
Of the teething gels, Dentinox works really well (and instantly) for Ava.