I agree with Mr. K. As soon as you are married, you should apply for her adjustment of status. As she has entered the US legally, the adjustment should be straightforward and once the application is made, she should be safe from immigration actions while it is pending.
However, until that time, she's on tenuous ground ESPECIALLY if she leaves the country. She will most likely be denied reentry and possibly even subjected to a period of ban on entry (even with the status adjusted). The ban can be lifted, but it takes more paperwork and more filing fees (we're going to be talking on the order of $2000 additional not counting what you're going to pay to an attorney to unravel the mess). She'll also not be allowed back while this is happening.

