Phonetic rendering:
吉 (jí) for "Je-/Gi-,"
奈 (nài) for "-nel-/-na-,"
尔 (ěr) for the trailing "-l" or "-r" sound (a common transliteration suffix, as in
哈佛尔 "Harvel,"
米歇尔 "Michelle"). The combo is standard for English/French names ending in "-elle" or "-nell."