This isn't about her temperment. This is an untrained dog who is doing the only things she knows how to get attention. Dogs do what works. Act up, I get attention, I keep acting up! You have to show her, gently and consistently, what you want her to do. Bad temperment is a whole other ball game. If she had a bad temperment, she would do damage when she bites (as an example).

Ignoring the behavior is effective, but you also need to give her something else to do. If you don't want her chewing on your sleeve, replace it with something way more fun--throw a ball, a stick, play a game, something Maggie loves!

Reward and praise her like crazy when she does something you like. My Chum is like this--he's just a little nutty and no one bothered to train him before. I ignore him when he jumps on me, after the knee to the chest trick. When Chum does something I like, I act like a royal fool praising him. He used to growl and carry on about being put back in his pen. Then one day he did it on his own and I just happened to be standing there. I acted like he was the smartest, best, most wonderful dog who ever breathed. Now he goes in the pen, sometimes when I don't want him to, just to get that reaction! The being a jerk about it has stopped!

Maggie needs to be to be socialized and trained--get thee to a class or buy some books, but get her trained before it does get out of hand.