yes we did, i stuffed a towel down the back of the mattress to shiove it over so it;s hard against our mattress. I'm going to get a kingsize flat sheet tomorrow to tuck in and make a seamless gap iyswim, but all the pics of sidecar cots on t'interweb just have them next to each other with a potential gap. I think maybe I'm being a bit of a worry wart.
Pressies sound right mhc. Ours (the two older ones anyway!) are getting one big present, a couple of medium sized presents, some books and a few stocking fillers and a tube of jelly tots each as well as their apple, satsuma and a "penny" from Santa. (and I bought a Wii but that is a joint/family present)
We also got each DC a wee present from the other two, but DS1 wants to wrap up his Duplo lego which is in the loft and give that to DD, which suits me as it's a really nice gesture, and saves money as well as stops us from filling the house with more tat.