Hi S.,
My oldest daughter decided she needed to sleep in our bed after she was given her own "big girl" bed at 2 years old.
It took 3 weeks of repeated trips back to her bed before she finally stopped coming to our bedroom to crawl in with her Dad and me. Each time I would walk her back to her bed, I would explain to her that she now had a bed of her own like ours and that is where she was to stay, unless she had to get up to potty. There were a few tears but after three weeks of consistently making her get back in her bed, she stopped trying.
I also told her that when the sun was shining outside and she woke up, THEN she could come get in bed with us and we made that a little "play" time with her - snuggling, tickling, laughing and telling stories.
P.