This was never an issue for me as a PNM, but as a sister I often had to rush two PNMs and it isn't easy to keep the conversation flowing and keep both PNMs involved!
For earlier rounds, I wouldn't mind a 2-on-2 situation with one sister, one sister from another chapter (or an alum), and two PNMs (like xo_kathy said, but I'd limit it to 2-on-2). If I had to choose between a double pick-up or being rushed 1-on-1 by someone from another chapter, I'd want the 1-on-1 provided I got rotated to someone from the "home" chapter at some point.
For later rounds, especially pref, I would feel unwelcome if I weren't 1-on-1 with a sister from that chapter. Schedule additional pref parties if necessary (I know, easier said than done
).