I think there will likely be tall people either place, especially on the basketball and volleyball teams.
Ha - no doubt. I probably should have said, tall, respectful, engaging, and fun. That’s it. 
Looks like all the main points have been covered, I would add that the athlete experience at a LAC can be truly transformative, something about the smaller setting and close bonding of the team and coaches is unique. At a LAC you can have compete a high level but also have a social life and excel in the classroom. That combination puts you in a great position for top grad schools or jobs post graduation.
An advantage for talented athletes at LACs is that one can play more than one sport (in different seasons, of course). Much better for non-scholarship athletes to attend an LAC in the Northeast US as travel distances for competition is not as burdensome as in the rest of the US.
In my opinion, the LAC experience is notably different than the mid to large school experience. A couple of semesters or an academic year of study abroad should be given consideration.
To me, experiencing diversity–in all respects–is an important part of higher education.
Most recently, I have had family members attend many undergraduate schools including Chicago, Brown, Northwestern, Harvard, and Duke in addition to a few large public universities. All of the elite private universities offered small classes, research opportunities, and close interaction with professors. All developed strong friendships during their university years. Not sure what, other than easier participation in intercollegiate sports at the varsity level, an LAC could have offered that was not available at these schools. (FWIW I have attended & graduated from both types of schools.)
P.S. In order to properly address OP’s concerns, it would be helpful to know the schools under consideration as well as more about the individual student.
When I look at my kids’ friend groups I see a mix of success from both large and small schools. One friend’s son who went to a LAC (not top tier but very good) had a hard time getting a job. Others have done very well. As have the kids that went to Penn State or Ohio State as well as other large schools. Are you looking only at kids that went to top tier LACs vs state Us?
The point is that this particular kid has to make a choice based on her preferences and path. Either path can lead to success.
I’m a tall person, too, and went to a large state u partly for the very reason mentioned- a bigger pool of tall males.
That said, my youngest is looking at the LAC v big u choices, too. I think it matters what is AROUND both the LAC and the big U. A LAC in the middle of nowhere (thinking Williams or Colgate) is a whole lot different from Southwestern (near Austin) or Rhodes in Memphis. My kid wants some sort of reasonable city around the college. Same with the U- is the U the entire town or is there more there?
This is definitely one of those personal choice things… D2 went to s small school in a town of about 8K and there was definitely not a lot off-campus options but she loved being there. The school had tons of organized activities on the weekend which helped fill some gaps.