Full size or mini

So we live in a bed room. My daughter who is one has her room my son that 5 his and our room we havr a newborn on the way. We will once baby start sleeping through the night wil be sharing the room with the youngest our daughter. If i rearrange her room i know i will be able to fit a full size but i know it will be tight. Im still trying to figure iut to to fit him in our room time being i think i could fit a mini crib in our room. Just not sure if i should or get a full size. We plan on moving just not sure when