Thanks guys. Would I wait for her to stir? It could mean me waiting outside her room for half an hour or so. But I guess that's easier than having to take her back to her room as she's now used to climbing in next to me - I barely wake up which is why I've let it go on for so long!
Yes I'll talk her through why she needs to stay in her bed. Won't mention baby, just, as you say, that she'll get a better rest in her own bed and then have more energy to play and have fun etc.