Ulayya
Yes. Ulayya is attested in medieval Arabic sources; a notable bearer is Ulayya bint al‑Mahdi of the Abbasid period.
Linguistically it is a diminutive/pet form of 'Ulyā'/'Aliyya' (علياء/عالية), meaning 'exalted' or 'high', so Ulayya conveys 'little exalted one' or 'young lofty one'.
No. The proper name Ulayya does not appear in the Quran.
Common pronunciations in English transliteration are Ulayya or Ulayyā, rendered approximately as 'oo-LAY-yah'.
Yes. Because of its classical pedigree, Ulayya appears in medieval literary anthologies and may be adopted by Arabic-speaking communities and scholars interested in classical names.