Jalīla
Yes. Jalīla derives from the Arabic adjective جليل (jalīl) and is the feminine adjectival form meaning 'majestic' or 'venerable'.
Yes. Jalīla is attested among Sindhi and other South Asian Muslim communities as a classical Arabic-derived female name.
No specific person named Jalīla appears in the Quran. The root and adjective are part of the Arabic lexicon used in religious and literary texts.
Pronounced ja-LEE-la, IPA: /dʒaˈliːla/.
Diminutives depend on local practice; 'Jali' or 'Leela' are sometimes used informally, though practices vary by culture.