Ann, what a brilliant idea you had with the walnuts!  If discussing sore
nipples this year perhaps a sample of some of the products expectant mothers
are advised to toughen their nipples with as a "preventive" measure
ante-natally - rough towel, buff puff, sandpaper and, yes, even wire wool.
Then you could encourage them to examine the vast selection of nipple creams
sold to "cure" sore nipples. Perhaps the OB/GYNs would like to really make
this a participatory event by taste-testing some of the creams?

Pamela Morrison IBCLC, Zimbabwe