1 Peter 3:1:
quote:
Likewise, you wives, be in subjection to your own husbands, so that if they do not obey the Word they may be won without a word by the behavior of their wives.
From a biblical perspective it wasn't a good idea for her to marry an unbeliever, but it's not a good idea to divorce the unbeliever, either. 1 Corinthians 7 says something similar, that if the unbeliever is content to dwell with the believing spouse, you should net send him/her away.
So, while it's awesome you want to look into things, it ought not to put your marriage at stake. Those verses allow her (command her?) to live with you with a good conscience.