Wow, were there a lot of articles simultaneously published about this UID, and lengthy, descriptive, well-written ones at that.
Her shirt is said in some accounts to be a "Blue Rodeo" men's hooded shirt made by Tip Top, specifically from 1995 until 1996, when a band by the same name demanded they stop using their trademarked name:
IMHO that shirt would've been quite in-style between 1992-1996. I was in high school then and those particular colors (reminiscent of the "Cross Colours" brand's scheme of black/green/red/yellow) and wide stripes were "in" but like KLDC620 said, they were pretty much out by 2000. Here's another Tip Top Tailors men's shirt that probably was made during the mid-90s, if I had to wager a guess:
If the UID died no earlier than 1995 (and I'm certainly not saying the shirt couldn't be a red herring and these remains couldn't be older) then maybe the watch was a hand-me-down from an older relative, borrowed from a significant other or even bought secondhand.
That tiny bit of red ribbon is the type of string you'd use to tie a balloon or gift, not something a woman would typically use to tie her hair back. I wish we knew more about the little red heart. It looks like something plastic that was once sewn or otherwise attached to an item that has since disintegrated, like an emblem on a sweatshirt, sock, or sneaker. (Although one would think that if the shirt survived, a sneaker wouldn't have time to disintegrate into nothing.)
<-- Watched one too many Hanna-Barbera "teenage detective" cartoons as a kid.