Yea, for kidding, definitely put them up in their own separate areas. It could lead to so many issues if there are multiple does in a single stall. Stealing and attention issues have already been mentioned, but the other doe could also crush the newborn kids.
I put mine in separate stalls, but they can see each other with the goat stalls I built. During my most recent birth, one of my does spent the entire time with her face smooshed up against the hardware cloth as her buddy gave birth next door. I think she was trying to be as close as possible, and did even try and lick a kid through hardware cloth, too. I think if she'd have been in the stall, we'd have had a Code Pink (hospital term for baby theft).