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.'" (JA)
English reference (JA): Vol. 1, Book 1, Hadith 305 (JA)
Arabic reference (JA): Book 1, Hadith 306 (JA)