This is her reply to my question:
I think the switch from the flat 3K to the steeple depends on the person. And it is hard to predict. A lot of times, my coach (Jay Dirksen of Nebraska) has picked out the tall women and asked them to try it, and so far the success hasn't been great. I am not tall (5'5") and he asked me to try it because, as he put it, I'm an all-around athlete (I grew up playing every sport I could and played soccer until college). Well, last year he asked if anyone on the team would like to try it, because no one was really that tall. The 2 girls that wanted to try it are both about 5'3" and petite in frame. I thought "Well, I'm not going to tell them they can't do it". They really amazed us: they picked up the water jump in a matter of days and turned out to be very efficient hurdlers, despite the fact that they'd never hurdled before. They went 4-5 at the Big XII Outdoor meet in the steeple. Neither of they had even been on a Big XII team before except indoors for the DMR. Rachel Carrizales went on to then place 5th at the Midwest Regional and qualified for nationals. She ran a PR of 10:17 at nationals. Although she failed to qualify for the final, she ran a very respectable time!! Her first official time of the season, back in April, had been 10:51. So she really disproved the theory that it is better to be tall.
In watching steeplechases, I think it is more likely for the shorter athletes to be more efficient and more flexible. Maybe that helps them in the steeple.