I answered my own question. I also included myself in the freelancers' tasks in that portfolio. When I created the filter for the report, I selected "equal" to her name since there wasn't an option for "contains." Once I removed my name, she appeared in the report.

I created a report to show projects/tasks for each of our freelancers. It works like a charm, only one specific portfolio will not show up in the results. I have the portfolio shared system-wide and set up like every other portfolio. I'm probably overlooking something very simple. Any ideas?