There is no cure for a ailment that is not know. If this has been happening since Sunday night then you need to get her to a doctor asap. There is no reason to wait this long. You need to be safe and have her checked.
Please see a doctor now..She can become dehydrated [loss of liquids] and become very ill. Usually coke soda will help, but it has been too long to home treat the child now..I'm sure you want what is best for your precious daughter..Take care
She sounds like she needs urgent care. Children dehydrate fast and that is life threatening. If she has not been keeping down clear fluids for almost 2 days she could be in trouble. Just take her to a clinic or an ER now.
If it doesn't seem too serious, put her on an effective diet called BRAT, for a few days just feed her plain foods like bananas, rice, applesauce and toast. Occasionally give her pepto bismol or a anti acid. If it continues get her to a doctor immediately.
So 48 hours is starting to get to the concerned stage. Did you try pediolyte? Is there a fever? She needs to go to the doctor if it doesn't improve by tomorrow. Don't let some responses make you feel like a bad mother. It's been 2 days!