Hey A.... Seriously, you're not suppose to give an infant under the age of 12 months anything other than breast milk or formula. Their kidneys are not mature enough to process water (or juice) out of their system... Giving them water (including an herbal tea) can cause "water intoxication" which is the primary reason for seizures in an otherwise healthy baby. No joke. PLEASE DON'T DO THIS.
"Giving an infant additional water to drink causes infant water intoxication by diluting the sodium in babies blood and flushing it out of babies body. That reduces the electrolytes in the babies body, altering brain activity, causing seizures to occur in the otherwise healthy infant."
http://www.associatedcontent.com/article/931669/infant_wa...
"The most common victim of water intoxication is an infant three to six months old who is brought to the emergency room either seizing or not breathing. The infants blood is too dilute. The initial treatment is intravenous solutions with a high concentration of salts. Sometimes the infant will spontaneously urinate large quantities of dilute urine to re-establish the normal salt concentrations in the blood. There is a risk of serious problems and even death from water intoxication."
http://findarticles.com/p/articles/mi_m0816/is_1991_Sept/...
FYI, my daughter was extremely congested as an infant. I once joked to her pedi that she was born congested... It turns out she has an allergy to cows milk protein, which caused her congestion. I suggest you cut out all sources of dairy from the baby's diet. If she is being breast feed, then the mother should cut all sources of cows milk from her diet (read labels; look for milk, butter, casein, whey) or if she is formula feed, put her on a formula that is not milk-based.