i posted a similar question on this forum a couple of months ago as we had just brought our 1st van and have a (then) 21 month old daughter who still sleeps in a cot. The advise i was given was the tomy bedgaurd for the bottom bunk. I went on ebay but with posting and packing it was still coming to about 20 pounds. I eventually brought one from Argos, cost 19.99. We have recently been away for a week, and i would make the bed up like at home with sheet and quilt, and slot the bedgaurd in place, my daughter slept all night. I was really worried about this and was considering having her in our bed but didn't want to set a prescedent as at home she would expect the same! But I needn't have worried, she took a little time to sleep as was all a little strange for her, but like the previous person said, children adapt really quickly. Hope this helps. p.s when we set up the bedgaurd we had to take off the long poles that usually go under the matress due to the small width of the bed, however it still works fine.