The Gypsy girl (who is probably not named Cher—although who knows?) is the only woman Safran actually loves. Not that he ever tells her this. Sure, he brings her flowers and chocolates ("all gifts from his widows" [27.27]), but all she really wants is for him to tell her that he loves her. He calls her "not-wonderful" (27.6) and "not-beautiful" (27.10) as though these are compliments, then he marries another woman, and the Gypsy girl kills herself later that day. We're not even sure if Safran finds out about the suicide.
But it's a serious relationship. They're together for seven years, and, even though we only see her on a few pages, she makes quite an impression on these pages, like when she sneaks into his house to see how Safran arranges his books, as though this will unlock some inner secret about himself. She finds that they're arranged by color and thinks, "How stupid" (27.123), offending thousands of Shelf Awareness readers everywhere.
On the day of the wedding—right before she kills herself—she passes him a note that just says "Change" (30.18). (And all he gives her are four ones and four quarters.) And you know what? He does change… eventually. He was probably loyal to Jonathan's grandmother by the time he met her.
Or maybe, by being loyal to Jonathan's grandmother, he was actually being loyal to the gypsy girl.