Abba – no offense but if it was that simple it wouldn’t have been a question. A 95 pound able bodied child with no sense of danger may need to be safely “contained” in a bed that would require a lot more than a large crib or chairs.
One of my friends bought a bunk bed and had the safety gates people use at the top of stairs attached to one side. The other side was against the wall. It worked well for her son.
hatzlocho