Toddler bed an adult can also fit in?

We got this cot that was meant to last from infant to 4 years (converts to go on floor with one side down for toddlers) but it already seems small for our two year old.

Her sleep is rubbish and recently she’s wanted hand holding etc at night so it would be easier if we could lie down with her rather than the awkwardness of reaching into the cot.

Does anyone know of a good bed that has some sort of sides to it (she likes feeling enclosed and rolls around a lot at night) that an adult could also lie in? Or maybe some people just use a normal double floor bed and put up toddler rails around it to protect them from falling out?