29F With red bumps/boils under breasts (updated with photo)

29F about 5’7” 150 lbs with very large breasts. This is actually for my girlfriend, she has I believe 38i bra size. I got her a thing that goes under your bra to deal with friction/sweat but she still gets them all the time, does this have a name? Or is there anything she can do to help with the irritation/pain? I have had irritation from my bras in the past but it’s never affected me like it does with her, but it happens even if she lounges around home and doesn’t wear a bra during the day.

She doesn’t smoke and take sertraline 50mg