Your daughter sounds very well-qualified. Both Pomona and Williams are amazing schools.
But because Pomona and Williams have such strong academic and D3 athletic programs, they are super-popular and get to pick from a deep pool of very well-qualified applicants. So I understand your concerns.
A couple of thoughts come to mind from my recent experience with my son.
First, has your daughter done an overnight visit at either or both schools yet?
The OV’s clarified a lot for my son about the teams, the social life, academics, culture/atmosphere, coaches, etc. It can be tough to make time for the OV’s, especially if your daughter has matches/meets this Fall, but it is well worth the time and effort. My son changed his mind about his preferences after the OV’s. I would highly recommend your daughter make the effort to do an OV at both Pomona and Williams if those are her top choices.
Second, after you get the pre-read, the coach will be able to give you a good sense of your daughter’s likelihood of admission, and can be specific about how his/her support impacts the admissions process. My son found the coaches to be pretty open, direct and transparent about both the process and his likelihood of admission. Both Pomona and Williams have a straightforward process that the coach will be able to explain.