I'm not an expert but I believe that the Herpes Simplex Virus can cause a breast infection. Sarah described a raised, red area on her breast which could fit with that. One thing's for sure though, if she has an HSV lesion on her breast she definitely should not be breastfeeding at all as the virus could be passed on to baby with potentially fatal consequences (as discussed here before).
If this 'sore on breast' situation is actually true (and not just a warped fairy tale to suit one of her twisted agendas) then I hope she really did visit her doctor to get it checked out. It really would be better all round if she just stopped titting about, put her scabby tits away and just got him on to a solely formula-based regime. If she refuses to stick some kind of plaster on her cold sore, to cover it, she really shouldn't be touching the feeding equipment either (particularly teats), so as not to contaminate and spread infection as she just can't stop touching her cold sore.
Is anyone here a health expert and able to clarify?