SilverTurtle, we have the same kinda thing in my chapter, its called a Lion Pal, and our big sis's are called our carnation sister (but we usually just call them our big sis)
a lion pal writes u motivational notes, gives u small gifts like a pen with letters on it.. or a picture of the chapter..something to keep.. i remember when i was a "phi" i was given this beautiful poem written on Phi Mu stationary and it touched me so much!! all my lion pal stuff i still have..
weird thing is i picked my big sister cause we hung out allll the time!! sad how things turned out but i have other great sisters in my lineage...