I had mastitis for the first time with my second babe. About the same time as your friend I think when baby was 6 or 7 weeks.
Above all, tell her to REALLY rest and stay in bed. Camp out with the baby in bed and have a nurse-fest, and stay bra-less. I used a hot-water bottle filled with boiling water from the tea kettle (you're not supposed to use water that hot in it, but it had worked for a firend who recommended it to me, and it worked for me too.)
I did pump a little to drain my breast as needed, but not too much b/c I didn't want to stimulate more milk production. I massaged the ducts that were clogged often.
It could be several days or a week before she is really feeling better. I tried to fight it w/o antibiotics for a few days, but when the fever crept up I decided to go for the abx. Suggest that she takes probiotics while on the abx and after, since the abx can be really hard on the baby's system.
Tell her to hang in there!
SAHM to a spectacular DS (5/2003) & delightful DD (2/2006 HBAC!)
“Unlike all other important jobs, parenting is the one job for which we get no formal preparation, education or training.” ~ Pam Leo