Ok, My daughter is a SUPER stubborn almost 4. Usually she's a pretty decent little kid, but when necessary we've been using the suppernanny time out technique. It works GREAT! But… 9 times out of 10 when time is up she refuses to come out. Then what do we do. We don't want to start a new argument now that she's done her time.
Glad to hear you have been using the timeout technique to perfection. Bravo to you! Where the child is slightly brewing over accepting the boundary that's been put in place, you may see, unwillingly, a reluctance to shake it off and that's when they turn the table around to try and make you come hither. Kids this age need a gentle nudge in a different direction to become engaged in something else. Casually ask her to join in the fun and, if she says no, then very nonchalantly tell her "You time out's done now, let's move on to this now." Stubbornness can be attached to pride, and she'll realize soon enough it's better to get over it and move on and have fun!