She was invited to attend the WNBA pre-draft camp and later on invited to attend the draft, so there were those who believed she could jump into the first round or perhaps early second round in the right situation.
Then, insanity ensued. Tamera Young was taken in the top ten (second round stock), and then Ketia Swanier was selected at #12 (again, middle second round stock). With these outrageous selections, the whole notion of "draft stock" went out of the window. After this point, teams just chose whomever they wanted regardless of how she fared during her senior season or at the pre-draft camp. They picked players whether they fit their systems or not. You'll note that a couple of second-rounders didn't make rosters, and two who did make rosters didn't do so with the teams that drafted them. And after seeing Yuko Oga play for Phoenix Saturday, I can see why the Mercury were going to cut Leilani Mitchell before New York "rescued" her.
What also hurt Kelly is that she's not as tall as listed (about 6'1 instead of 6'3), and she appeared to be physically weak against WNBA-caliber posts (lack of bulk hurts). Still, that's not a good enough reason as to why she couldn't make Houston's opening day roster. Walker, Williams, and Holmes aren't what I would consider to be WNBA material. If she'd gotten cut by Seattle or LA, that might be a different story. But Houston? Hmm. Might be some red flags involved.