Hi Tina,
It sounds like your mom may have nipple vasospasams, similiar to Raynaud's
syndrom. I had a client who had sever nipple pain, nipples were pink so she
thought she had yeast but this mom had no other risk factors or sx. After a
fdg the nipples were creased but I found this from the baby's defenses to cut
down mom's flow. After the nipple started to return to shape then the
blanching would start. The pain would be intermittent during the day not
associated with fdgs.
Check the archives, there is alot on Raynaud's.
She may also have yeast, and the baby's  palate could be playing a role. To
have the baby's palate evaluated by an oral/speech therapist might help.
Good luck.
Ann Perry RN IBCLC
Boston, Mass