Once your baby is six months old, you can begin giving water in small amounts. This is the time when you introduce solid foods, and also when she gets more active. You can also offer diluted form of fruit juices (1:10 of juice and water), but not soda or other sugar drinks. You may start with a sippy cup or bottle feeder.
However, excess water might result in her tummy pain or any other discomfort.
In rare cases, a baby who drinks too much water can develop a condition known as water intoxication, which can cause seizures and even a coma. Water intoxication happens when too much water dilutes the concentration of sodium in the body, upsetting the electrolyte balance and causing tissues to swell.