Room Sharing

Here’s our situation:

Our son who is now almost 4 months old sleeps in his crib which is in our master bedroom. With our living situation, this will continue until he is about 1 1/2 years old.

We’re planning to get a room separator so that when he gets up in the middle of the night he can’t see us, because I’ve heard that if he can see you there he might cry just because of that to get your attention.

So what my question is, is that when should we get that room separator and if anyone else has done this or something similar and what the results were.

Thanks guys!