My 3 year old has projectile vomited for 9 nights straight!?

She contracted the flu about 9 days ago (vomiting mostly, occasional fever) and I joined her about a day later (vomiting, diarrhea, no fever). Mine lasted for 7 days! She is still sick! At first, couldn't even keep water down, but at end of flu it didn't bother us to eat, although we'd vomit after. She vomited last night with uncontrolled diarrhea after playing like a healthy kid all day and eating. What could this be?