From birth with both girls. We have had 2 in bed for the past 9 months but today is DD1s 3rd birthday and we have explained it is time to start sleeping in her bed. She has had a bed for about a year and some nights she will go to sleep in it but always ends up in our room before morning. She has some sleep issues though. She wakes up in hysterics multiple times per night and has since being an infant. DD2 sleeps way better and probably doesn't even need to cosleep but I like it for nursing and knowing where they are. I think she will be an easier transition when she weans (maybe around 2)
Mommy to Fiona 12/09 and new baby Layla 3/12 a HBAC!