Toddler stomach flu

Can I give my toddler Tylenol for stomach flu? She hasn’t had a fever all day and it just spiked to 102. She was puking from 1230am-1030am, and it seems whenever we give her too much fluids she gets sick again. We’ve been doing about a 1/8th a cup at a time. She can go a few hours without getting sick and then all of a sudden gets sick again, I’m not too sure why.

We had her in earlier for possible dehydration where they gave her Zofran, and it helped for awhile and she finally kept apple juice down but now she’s just sluggish.

Is there a certain point we should bring her in again?