The Quran

فَلَمّا وَضَعَتها قالَت رَبِّ إِنّي وَضَعتُها أُنثىٰ وَاللَّهُ أَعلَمُ بِما وَضَعَت وَلَيسَ الذَّكَرُ كَالأُنثىٰ ۖ وَإِنّي سَمَّيتُها مَريَمَ وَإِنّي أُعيذُها بِكَ وَذُرِّيَّتَها مِنَ الشَّيطانِ الرَّجيمِ

Muhammad Asad

But when she had given birth to the child,¹ she said: "O my Sustainer! Behold, I have given birth to a female" - the while God had been fully aware of what she would give birth to, and [fully aware] that no male child [she might have hoped for] could ever have been like this female² - "and I have named her Mary. And, verily, I seek Thy protection for her and her offspring against Satan, the accursed."

Lit., "to her" - implying that it was a girl.
Lit., "and the male is not [or "could not be"] like the female". Zamakhshari reads these words as forming part of the parenthetic sentence relating to God's knowledge, and explains them thus: "The male [child] which she had prayed for could not have been like the female which she was granted" - which implies that Mary's excellence would go far beyond any hopes which her mother had ever entertained.