Hi,
        In a great article on LAM ("Guidelines: Breastfeeding, Family
Planning, and the Lactational Amenorrhea Method-LAM" Institute for
Reproductive Health, 1994) for birth control the authors note that extended
periods without nursing can encourage fertility to return sooner. "Intervals
should not exceed four hours during the day and six hours at night and
supplementation should not exceed 5-15% of all feeding episodes."
        If the mom were to do the opposite, ie, encourage a six hour stretch
each day where the child doesn't nurse maybe she'll have menses and
ovulation return. I would think if they are doing family bed that night
isn't going to be it  (baby could be moved to sleep on the other side of Dad
so that she's less likely to nurse frequently through the night also)-- but
what about from waking until afternoon -- most toddlers can be distracted
during this more alert time of day with other foods, and water and playful
interaction.

Hope this helps,
anne
Anne E. Robb, MAT, LLLL