Potty training = epic fail

Meg had been doing so well on the potty training front. She was ready. Then she did it! My girl went from diapers to panties and didn't look back.

Except. Well, now she's totally looked back.

So during the week, she doesn't mostly well at school. But once she's home with me, no amount of prodding, bribing or "racing" to the toilet seem to make a difference. Andy has become a champ at fake-racing where he tries to motivate her to go by challenging her to a, "Who's first? I'm going to beat you!" race. But even that has lost it's appeal. As a result, she has ruined about a half dozen pairs of girls panties (actually, they may not have been ruined, but I was not in the mind to do the scrubbing necessary to save a $.50 pair of girl's underwear). It's gotten so bad I practically have her in diapers or a pull-up most of the time at home because I was tired of cleaning up the carpet from accidents. 

Any tips out there on battling potty training regression? I know she can do it, but she's still a two year old for another couple of months and I have (somewhat) learned it's not worth it to get into a battle of wills with a person that age.