The ripped shirt...?

I came home one day and saw this...

I asked Cory what had happened and he claimed that when he got her up from her nap he found her just like this...? haha

Now, has anyone else had this happen? After laughing for like 10 minutes I knew there had to be more to this story. Finally like 2 days later Cory did say the shirt was ripped, just not all the way, he gave it a little tug to see how it could have ripped so easily and the rest ripped. 

So the verdict is still out...how did she do it? And was she alone? She has some mad skills but this one is still blowing my mind!