Maybe she was blinded by her husband's flaws. We tend not to see in our loved ones anything wrong. But I don't think that makes culpable. It was her husband's CHOICE to cheat on her and break their marriage vows. It has nothing to do with the life she tried to build together with him. As far I can see, Matos McGreevey was by all accounts a model wife and mother.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus