We've always allowed the girls to sleep with us when they need to. We've always encouraged them to sleep in their own beds, but when the room is too dark, they don't feel well, or they just need to cuddle, they are welcome with us.
They will be grown very soon and we will be left with very sweet memories of cuddling with our girls. (I have very fond memories of sleeping with my parents at night when I was little).
The other night Thea just needed Papa. She made no excuses about coming to our room. She just wanted Papa. She said she needed him "'Cause he's a good snuggla". (snuggler)