Sister,
All you need to do is fill out the Potential Member Profile, which you can download at
www.alphadeltapi.org. Send it directly to the UF chapter.
If you'd like to include a personal letter to accompany the form, feel free to do so, but it is not required. This can be a brief note endorsing the PNM for membership and sharing some of her posititve attributes-- maybe taking some words from our Creed and matching them up to her accomplishments (IE: leadership, responsibility, high educational standards, loyalty).
Good luck to you both! UF has so many great sororities; I hope she will have the opportunity to join one this fall.
ETA: If anyone is wondering, an ADPi collegian may send a reference for a PNM at another university.