Abu As-Samh said:
"The Prophet (ﷺ) said: 'A girl's urine should be washed away and a boy's urine should be sprinkled with water.'" (RU)
English reference (RU): Vol. 1, Book 1, Hadith 305 (RU)
Arabic reference (RU): Book 1, Hadith 306 (RU)