It sounds like she is testing the boundaries. The fun part of parenting is the fact that our children are constantly changing, and constantly testing us. The best advice is just to keep putting her in time out, even when she gets up. When she gets up start her time over, and make sure that you're not putting her there too long. children have a limited capacity for understanding punishment, and especially that young, they can't remember what they got put there for if the time out is too long. The general rule I've heard is 1 min for every year old they are. Also make sure that when her time out is up you discuss with her why she got put there, that way she knows and can hopefully learn to avoid it in the future. I don't think that her new attitude has to do with her grandma's comments, probably more to do with the age she's at. They love to test the limits and make sure that what was not okay yesterday, is still not okay today. I hope this helps, and good luck!