Hi Moira
Welcome - I'm glad you found your way to this site.
A sore mouth is common during chemo, and some women find it helpful to rinse their mouth a few times a day with bicarbonate of soda. Some women also switch to a child's toothbrush because of the gentle bristles.
There have been a few blogs about sore mouths which I have included below. Check out the blogs as well as their comments for hints from other women.
http://www.bcna.org.au/user/6639/blog/24074
http://www.bcna.org.au/user/8967/blog/31066
http://www.bcna.org.au/user/9736/blog/31428
Good luck Moira. Your friend is lucky to have you around.
~ Annie - BCNA Policy Officer