Valid question, but in my opinion and one who swims with his eyes open she should not have any issues. I'll address the specifics and possible exceptions. The sand in the pool is a clean white sand that varies in depth in different sections of the pool from a trace to maybe 6 - 8 inches.
It does feel good on tired feet when you wade where the sand is deeper. The sand tends to get deeper in the center of the pool and under the bridges. Unless she's swimming close to the bottom and/or no one is kicking up a lot sand she should be fine. The lazy river portion of the pool is deeper than the rest of the pool so the sand is a good 6 - 7 feet below the surface. Others may have different experiences, but thought I would "anchors aweigh in".