My wife had mastitis, then nipple thrush and then mastitis again while breastfeeding in a 2 month span. does she have an immune problem?

Likely not: Thrush is very common illness. If her nipples hurt due to the yeast infection the first time, she might not have aggressively fed on that side as normal, lending to the mastitis. Since thrush is difficult to eradicate, it makes sense that it came back. If odd infections occur, it's good to think about immune deficiency, but unfortunately, or fortunately, these all make sense.

Doubt it: Mastitis is an infection in the breast. It is most common with breastfeeding. Ducts ofter get clogged, the milk backs up with bacteria and infection occurs. She should continue to pump while being treated. With the thrush, it is important to have the baby checked and treated as well. Work with you pediatrician and gynecologist.