DS is now about 13 - 14 months. We have used an armsreach co-sleeper but it says you are supposed to stop using when they can sit up by themselves.
However, we have ahem, carried on. We figured it was safer if anything than Ds cosleeping without his own space, as at least he has the sides to stop him rolling off the bed. Also, he wears a sleeping bag, which impedes his mobility a bit at night.
He is going to get a bit big for that cot though - but he is too small to sleep in his own little bed. It would be great just to move him into a bed - even one by the side of ours if he's more comfortable there - but when would it be safe?