I guess the question is what would qualify as a "US Distance Star." I don't think running 14:40s-50s would. Right now we have 14:20-30s runners who are great (Monson, Cranny, Schweizer), but I wouldn't say they've become huge stars mostly because they've looked overmatched in global competition. Molly Seidel became a star because she got a medal at the Olympics. So, I think if we go beyond "could Parker Valby become a Monson/Cranny type" which most people would believe is highly possible, it's whether she could become even better than that. Unless she can up her training a lot, I'll be a bit skeptical. It's great that she runs so amazingly with cross training and not much actual running, but it seems rather unlikely you could compete with the Hassans, Gideys, Tsegays running 1/3 as much as them.