K.S.
My oldest daughter is in the exact same stage...she was finally having dry pull ups, so we would switch to panties and she would start wetting the bed. So we started the following routine: after a wet panty night we would go back to pull-ups and she would have to have three dry nights in a row before getting to wear panties again. She could wear panties until a wet bed night, then back to pull ups. Wearing panties became such an achievement that she started having more dry nights. She has now gone about 10 nights in a row wearing panties with no accidents. We give her lots of praise and "high fives" each morning she wakes up dry. To ease the pain of doing so much laundry (plus I hate making the bed so much) I bought a couple of mattress pads from babycenter.com that actually go over the sheet and tuck under the mattress; they look kind of like a wide belt that goes across the bed. If she wets, I only have to take off the pad and replace it with a dry one. Much easier in the middle of the night than making up the entire bed with new sheets!