To summarize chabad.org, Quinoa is not chametz, so theoretically, it should be kosher for Passover. If you follow Ashkenazi minhag, then you may have the issue of kitniyot. Some halachic authorities consider quinoa to be kitniyot, thus not kosher for Passover, but others consider perfectly acceptable. Additionally, packaged quinoa may be processed in the same facilities where wheat is processed, creating the risk of contamination with chametz. But in general, quinoa should be okay.
In this case, I think it would be best to ask your local rabbi. He/she could best address this question.