"..to establish a perpetual bond of friendship among its members..." is one of the main purposes of Tri Delta. We strive to promote and strengthen bonds between our members by holding various sisterhood events. Immediately after Bid Day new members are paired with a Big Sister. A Big Sister is an older member who not only gives the new member presents but serves as her mentor throughout her first semester and following college years. Big Sisters really help new members feel at ease while transitioning into college and the sorority. 
Shortly after Bid Day, new members can meet and bond with each other during our New Member Retreat. The New Member Retreat is a sleepover at the Delt (our house) which involves fun activities that help the new members bond and learn the history of Tri Delta.
The sisterhood events we hold change with each semester, but have included Big Sis-Little Sis shopping trips in San Francisco, movie nights in our living room, and ice cream socials.
