Biur Chametz

Question

I have heard that it is okay to do the act of Biur chametz by flushing the findings from the night before down the toilet. On Erev Pesach (tomorrow) I will be heading out to work early in the morning. Would it be okay for me to eat breakfast and do my own Biur (toilet method) early (6:30 am) having the intention that I nullify all chametz that I own eventhough my parents will be getting up later that morning and eating chametz? As a side note: I am a female Sephardi - am I obligated to do it? (the rest of my family is not as observant but I think it is necessary to do it).