Stomach flu or food poisoning

My step daughter dad a visit with her mom yesterday and they ate Taco Bell, she told her mom after she ate her food her belly was hurting, but after we got her back about 10 pm last night she was throwing up everything she ate last night. She had a low grade fever last night didn’t have another fever again until now.. only other symptoms are watery eyes. What do yall think.. flu? Or food poisoning? I have two other littles and really praying it’s not the flu