So Jamila is a Muslim who drinks alcohol and eats bacon? I've met Muslims who do that but they weren't that Muslim.
Having lived in a Muslim country for awhile(SEA), in my experience they are pretty common esp if they can relax around you since you are non-muslim. That said, Muslim has become mandatory in many regions as a "race", and not a religious choice. You will be stripped of many privileges if you declare yourself non-muslim, that's why most just keep quiet about it.
That said, having a random muslim in this world is kinda weird. People who choose to stay muslim in an environment where most are non-muslim are typically very religious. They made their choice to display the religion as their identity and want people to know for specific reasons.
So unless we discover her husband or father was forcing that on her, it wouldn't make sense.