My 4 year old suddenly vomited around 10pm got her cleaned up and to bed and at 11:30ish she started to vomit while sleeping since then she has been retching with no vomit for 3 hrs every 15 mins or less. Gave her water and Sprite and she fomed up on her next attempt to puke. She isn't waking up to get to the trash can if she has a small amount of liquid coming out. How long do I let this go on before I take her in?