Oh no! Well gripe water, despite the misleading name, is not water! So straight water is not really a good substitute. I hope your baby is feeling better though :)
Why do you want to give her water is an important part of the question I think. It is very dangerous to give a baby that little water. It fills them so they eat less and can cause imbalance in their electrolytes. But I assume you have a reason for wanting to do so... So maybe if you told us we could help you brainstorm other solutions :)