The second she starts demanding attention I would ignore her. If she does not stop I would immediately put her in time out in a crate. I wouldn't wait for the behavior to escalate. It sounds like she started a behavior, didn't get what she wanted, and got more demanding. You have to be consistent. You can't let her push sometimes and then not others. You'll need to make sure that every time she does X you do Z.
Murdock - GSD
Virgil, CGC - GSD
Tara, Reagan, Madison, and Jefferson - Aussies
The birds: Dante - CAG / Nero and Sunshine - Budgies