WAGE GAP/When to ask for raise

Is it real at your workplace? I went to trade school and make less than those who don’t have any schooling. I’m an Esthetician and manage a beauty bar. I don’t make shit.

I started in a “90 day trial” which I’m almost out of and is clearly going well. I absolutely need to make more than I’m making. My workplace is pretty casual, as is my working relationship with my boss.

Do i bring up a raise in casual conversation or formally email requesting one?

Mind you, my boss is female.