Hi All,
Linda, my questions would be:
1)  How long does the soreness last?  Is it only for a few days, then goes
away?  If so, I'd hazzard a guess that it is hormone related, even tho her
periods have not stabalized yet.  Personally, I had no nipple tenderness
before my cycles before, during and after BF my oldest son.  But after the
birth of my 2nd son, when I got my cycles back, OUCH!  For about 4 days they
would hurt and be a tad red (almost so you couldn't notice) and it took a few
months before it dawned on me that it was hormones related to my mentrusl
cycle.

2)  Is she pregnant?

3) Has she tried treatment for yeast as a "just in case"?  Sometimes
babies/toddlers can be asymptomatic with thrush, and since she has been on
antibiotics she may be in the process of devloping the yeastie beasties.

Let us know what happens!

Jay Simpson, CLE