Empathize with her emotions, not her situation. If you don’t know what it’s like to be where your friend is standing today, don’t try to tell her that you do. Instead, be honest and tell her that you can’t imagine how she feels. If you’ve been in a similar situation, or know of someone who has, don't try to minimize your friend's experience by making it seem less severe in comparison.

Keep your advice limited. While you're probably experiencing feelings of anger and hurt for your friend, now is not the best time to express how you feel. It won’t help to tell your friend what you think of her boyfriend or what you think she should do in retaliation. Instead, focus on letting your friend air her own feelings and be available to listen and support her.

Don’t try to explain the affair with comments, such as “The affair was all about sex” or “I saw this coming after all of your fights.” You don't know why the affair took place -- the situation surrounding an affair and the reasons for cheating are often complex, and assigning blame doesn't acknowledge the complexity of the situation that led to cheating. Now is also not a good time to confess you suspected it. Nothing good will come from the confession, and it can make your friend feel stupid if she had no idea.

Offer concrete help to support your friend while she heals. You can offer to watch the kids, tidy the house or make dinner if she needs some time to herself.

Help your friend regain her self-confidence by telling her about the qualities and characteristics that make her a wonderful person, such as her kindness and compassion, sense of humor or bravery.

Treat your friend to a dinner out -- just the two of you -- or book an afternoon at the spa and let a little pampering help to put a smile on her face. Shopping might help to cheer up your friend for a while. If going out isn't in the budget, pile your pampering supplies in a box, head over to your friend's house and make it a girls' night in with makeovers and manicures.

Plan a getaway together for some much-needed rest and relaxation. The planning will help to get your friend`s mind off her troubles, and the trip will be something she can look forward to and enjoy.

Encourage your friend to take the time she needs to process and sort through her feelings rather than encouraging her to forgive or leave her boyfriend. She needs your belief in her that she can determine what is best for her. Reassure her that you will be there for her throughout the healing process. If she needs more help than you can offer, recommend that your friend seek professional counseling.