When did your BF baby start going longer at night?

[Marythefairy]

My dd1 slept for 7-8 hours from 6 weeks and with the odd blip was sleeping through from 3 months. Dd2 has never been a good sleeper at 8.5 months 2-3 hours sleep between feeds is a really good night. Sometimes she wakes after only half hour asleep.