Dr Jack,   Been thinking about this since I read your  post about the Lesbian
Couple and breastfeeding.  I have been in this situation a couple times in my
25 years plus as a LLL Leader and LC.
IMHO babies come with one biological mother, the one with the milk since we
are mammals!  Therefore, any other parent, support person, GMa, Auntie etc.
gets to care for our off spring with loving attention etc, etc...all the other
baby/child care tasks that come with the baby....everything except
breastfeeding (giving milk from the breast!).  I would encourage this family
the same way I would any other two parent family...other parent can do
everything for baby, the only thing she can't do is breastfeed.
The few lesbian families I have consulted with have felt that this attitude
was helpful, considerate and supportive.
BTW, Thanks for asking...I'm enjoying the different opinions.
Karen Evon, IBCLC
Sacramento CA , Sunny today...between storms.