I worked in a sitdown pizza chain many years ago where some of the managers would work shifts as servers because they made more money that way.

I got fired from Sequoia on the Georgetown Waterfront, when they wanted to keep me in indefinite training, so as to keep from having to pay me tips. They told me training would be between five and seven days. On day 10 I complained and was fired. This was for bar backing. And I was the only one who spoke native English and wasn't from south of the border. I later found out all those others had been in training for over a month.

I worked for a pizza place where the food was excellent but the owner was a Napoleon tyrant, double digit IQ, ego larger than life.
He took all the cash out of the drawer and took off to the titty bar after dinner rush.
The inmates ran the asylum...but most were first class inmates who worked their butts off and made that guy money hand-over-fist.
That place did good business and could have done more.

Anyways, I was owed almost $1,000 in proven overtime which was a much bigger deal back then. About four months rent for me.
(it was right there on the paycheck stubs.)

I wanted to become a shift manager and have a title.
I knew every process of the place and offered a wage even below what he was paying the dorks.
(plus half the employees had just quit en-mass in protest of him.)

I was a bit forceful perhaps.
I showed him my pay stubs and just wanted half the money owed plus manage the place.
He told me to bugger off and put a dollar on the table. Get the f'k outta here punk.
Then later he called "spoke with his attorney" and was very very nice.
His father was left for dead on the couch for three days and he was about to win a huge lawsuit and fold the store for good.

Moral of the story:
If she doesn't need a reference is going to leave anyways....document...and go big.
She would be helping other employees as well.