In this episode Jackie, a rich and spoiled girl had to get a job (or "got a job"), (*)because she had to choose between this boyfriend or her father allowance. She and Kelson, her boyfriend, were dating without her father knowing.
Or it could be:
(*)because she was made to choose between having a boyfriend/dating this boyfriend and her father allowance.
She and Kelson, her boyfriend, were dating without her father knowledge.
(To me it may imply focus on awareness pure and simple, perhaps her father would accept their dating if a bird told him afterwards?)
She and Kelson, her boyfriend, were dating without her father knowing.
(To my thinking, here one assumes that she is doing something prohibited/not approved of by her father, should him know that, he certainly wouldn´t accept.) The focus being on her father permission/consent or lack of it.
"How can i read my girlfriends text messages on my phone without her knowing"
That is, if she knows, she certainly won´t approve such a thing.
Anyway, it would be my word choice, though.