I remember reading a study many years ago that found that about 80% of
babies "sleep through the night" at around 3 months, and that at 6-7 months
most of those babies begin waking again several times a night! It is not
related to breastfeeding, just normal childhood developement!  My first, my
only crib baby, I would find practicing new skills, like pulling up in the
wee hours.  The rest I have just nursed back to sleep before they are fully
awake.
When parent say my baby "slept through the night at 2 months", they don't
tell you it only lasted a few weeks.
Patty Spanjer, RN, IBCLC
Dalton, Georgia (north georgia mountains, almost in Tennessee-Carpet
Capital of the World)