Providing Applicant Information to Third Party

Q I have a potential applicant at my Section 202/8 site who is being informally represented by her sister. The helper-sister routinely handles most of the applicant's affairs and wants to sign application materials on her behalf. She would like to receive a copy of the notice when her sister is called from the waiting list. The helper-sister is afraid the applicant-sister will not understand the notice letter and miss her chance at admission. Am I allowed to send a notice to the applicant's sister?