tony's gonna be around 45, so maybe it was his younger brother that she was engaged to? i figure he's got his own kids so that's why he didn't fight for custody of his niece, but he's around to help mercedes out with whatever she needs. his parents will also be there for them too - i don't think they ever got the whole biker thing, and they worry about tony being involved in it, but mercedes was almost their daughter-in-law and they'd still be close with her, i think.