Do people in arranged marriages ever fall in love with each other?

Yes, quite often....they learn to live with each other and sometimes fall in love.

I’ve heard some say that they can grow to love each other.

Yes. I've worked with & socialized with a few couples who were in arranged marriages, and they all fell in love with their spouses over time.

yes, I know a Muslim girl in an arranged marriage and she is very happy

Sure.

Yes when Stockholm syndrome kicks in.

They would be lucky if they do