Page 5 of the rules says if there is no room for new family member, it shares a room. For how long can it share a room? Is there some kind of penalty, IE: can't use family member until it gets it's own room?That rule is ONLY talking about the "Family Growth Even Without Room" Action space in Stage 5. The standard "Family Growth" Action that becomes available in Stage 2 REQUIRES that there be an empty room for the new family member (i.e., you have more rooms in your house than family members).
However, when the Stage 5 Action is taken, that family member can share a room for the rest of the game if you want, with no penalty. However, you still cannot use the Stage 2 Action until you once again have more rooms than family members.