I think theres been a thread like this recently but I couldn't find it. My DD1 is nearly 19ms old and DH and I are thinking of changing her cot into the bed over xmas. She loves lying in her sisters bed next to her when they are reading together so we think she may be ready for this step. She does roll around alot - you hear her crashing into the side of the cot at night so a guard will be needed. How old were yours when you converted?!