They are hiring as a consultant/contract NOT an employee. This means you don’t get benefits, including unemployment if you get let go. It also means that they can’t tell you HOW to do your work, just what results they expect.
20-35 hours/week and $35-45/hour, which is pretty good. Virtual assistant work would only get you about $25/hour.
http://philanthropynewsdigest.org/jobs/55462-administrative-assistant-contract-consulting-position