Hi,
How is your mom? Can you elaborate on the sticky discharge coming out from between her breasts? Burning sensation and pain may point to neurological causes and needs to be evaluated further. If her pain medications do not help, she may need to have a stronger prescription medicine as well. Direct clinical examination is important. Take care and do keep us posted.
I'm not a doctor, but that doesn't sound right (at all) to me. Did the doctor(s) say she had an infection at her incision site after the bypass? After almost 2 months, that incision should be well on its way to healing. I would call the surgeon (not her primary doctor, etc.) and ask for an appointment so they can examine your Mom and find out what's going on.