[AnchorAlumna]

I have no details about this particular situation, but here's how it usually goes:
At the beginning of formal recruitment, the new sorority makes a presentation of some sort to all the PNMs. Then formal recruitment takes place, without the new group participating.
A few weeks after formal recruitment ends, the new sorority announces that it will be colonizing and advertises for PNMs to sign up for interviews. A big meeting takes place, with girls signing up for interview times.
Then a committee of some sort, usually involving both international, regional and local sorority officers, interviews each girl.
Invitations are issued for a recruitment-like round, with a neighboring chapter's members doing the rushing.
Then invitations are issued for a preferential party, with a different neighboring chapter conducting the party and pref ceremonies.
Then bids are issued.
The process takes about a week or two. That's just a rough idea of how it goes.
Recommendations are highly suggested, and can be sent to the sorority's international headquarters.