WebMD has an article today about the potential for canola oil to diminish your daughter's risk of breast cancer. The findings are based on a study done with mice, so there's more research to be conducted before we can known with certainty.
Nonetheless, it couldn't hurt to make the change from corn oil to canola. It's good for you.
See the article here http://www.webmd.com/breast-cancer/news/20081117/canola-oil-may-affect-breast-cancer-risk?ecd=wnl_brc_112508