6 months baby should normally be passing urine frequently..if she has not passed urine for 15 hours according to you, then you should see your nearby paediatrician....In the meanwhile continue breastfeeding if you are doing so/ or else start formula milk...hydration is very impirtant...amd more important is to find out the cause/reason for the low urine output
Next Steps
visit your paediatrician as soon as possible for a thorough examination and counselling.
Health Tips
1) If your milk output is less, you can safely give formula feeds ..2) Also at 6 months gradual weaning can also be started...3) Check the diapers frequently to know the urine output..Take care