Bassinet to crib transition help

My cousin currently has a 4 month old that she has in a bassinet. She lives in an apartment and would like to move him to his crib as he is rolling a lot more now, but since her apartment is small the crib is in the other room. She is not ready to have her baby sleep in another room.

Is there another type of baby bed that’s small enough to fit in her room but safe to let her baby get bigger in?