My 2 year old was EBF for at least 3 months and began STTN at 4 wks old, on her own, I did NOTHING to encourage it. We do not bed share, but she was in a cradle at the foot of the bed until 4 months old, then in a crib in her own room
My 6 wk old will randomly give me six hour stretches. Sometimes during the day, sometimes at night, sometimes, like the last two days, 3 hours is the longest. She is still completely EBF, and still in the cradle at the end of the bed.
But, like the previous poster, I EARNED these stretches. My oldest, 14 now, was not STTN until she started school. I clearly remember driving around with her at 3am, 5am even some nights. And she was totally formula fed!