People's names should not be translated. Their pronunciation is
the same in English and Spanish. Some first names have a Spanish
counterpart, but it is improper to call someone by a translated
name unless that person uses the translation first.
Re pronunciation: a Spanish-speaker unfamiliar with English
pronunciation may well 'read' the name as
'Meel-yee-THENT (Meel-yee-SENT in Latin America) bahnYON'.
To enable them to 'read' it with English pronunciation, you
could write:
'Milisent Banon' with accents on 'Mi' and Ba' and tilde, ~, on
the first 'n' in Banon.
It would still sound a bit Spanish (Mee', not 'Mi', for
example), however.