DISCLAIMER: My chapter has not recruited this way before, though I would like them to in the event they need just a few NMs. We've just had informal recruitment
parties. I do advise, but I'm not the recruitment advisor.
I'd say the best thing to do would be to have the sisters gauge their friends' interest level in joining your chapter before inviting them to meet more sisters. You don't want to waste your time on women who aren't interested, but you don't want to seem pushy or desperate by telling them that immediately.
I think it'd be a good idea to have the PNM hang out with a sister she already knows and 1 or 2 sisters she doesn't know . You can do "normal friend activities" with her (as long as they facilitate conversation; going to the movies is a bad idea) and then decide who to offer bids to.
Have you talked to your advisor? Your advisor, ABC, and CPO are there to help you and they may be the best source to offer a strategy tailored to your campus.
Come on over to the Sigma Kappa forum, btw.