This repulsion is stronger than the repulsion between the lone pair and the three bond pairs on the nitrogen atom. Since the repulsions on the bond pairs in H2O molecule are greater than that in NH3 the bond angle in water is less than that of ammonia.
“Since the repulsions on the bond pairs in H2O molecules are greater than that in NH3, the bond angle in water is less than that of ammonia.” Hope this helped!
