If baby monitors didn't exist, what age is good to move baby to her own room.wat wld be a naturally good time?

I would say that depends on where the baby's room is - how far from your room? If the baby's room is right next to your room so you can hear her fussing or crying without a monitor, then you could move her in there whenever you feel comfortable with it. If baby's room is on the other side of the house or upstairs or otherwise out of earshot, then not until she is old enough to get out of bed and come find you if she needs something - maybe 2 years old?