heh, well, my grandfather is an initiated member of a fraternity at U Penn (no idea which one, he doesn't talk about it, never mentioned letters or a badge or anything, although I'm sure he has them somewhere) and he is a social member of Phi Kappa Tau at Bethany College (Phi Chapter) . He donates $$ to Phi Tau and Bethany, and all of his friends are Phi Taus from Bethany and they are his war buddies. He was proud as punch when my brother joined the SAME CHAPTER. My brother has never given my mom any letters to wear.I know she'd love a mother's pin too. Come to think of it, I've never SEEN him in sewed on letters, mainly because his girlfriend wears them all the time.
I bought my brother a pair of skull and crossbone letters (with a yellow background on a black shirt) for christmas because he was jealous of my skull and crossbone on red on black shirt. So we'll be very similar to eachother. Although mine have a much deeper meaning, but his are similar to the Pittsburgh Pirate colors
. If he gave me a phi tau shirt to wear, I'd wear it, but I think that those are kept under wraps.
I don't think that my chapter lets our moms/sisters wear our letters, it's never come up. I'd love to make my mom a (letter letter) mom shirt.