Definitely get her the sweethearts pin located on on the Sigma nu website.
http://www.sigmanu.com/store/hqstore/
Miniature Initiate Badge (used for pinning, sweetheart's pin, etc.)27.00
Sweetheart Pin (for sweethearts, mother, sisters)8.00
Also screen printed rush shirts would be fine as long as they weren't the double stitched or appliqué letters.
NEVER our badge or the double stitched or appliqué letters
Just my feeling on it.