When your friend is upset with you for talking about her to another friend, the first thing you have to do is offer a sincere and heartfelt apology. Author, researcher, CEO and founder of Psych Central, John M. Grohol, Psy.D., says there are four parts to offering a sincere apology: acknowledge the wrongdoing, accept responsibility for your behavior, try to repair the damage you've done and promise your friend you won't talk about her to another friend again.

Showing empathy to your friend means that you understand your friend's perspective and feel her pain, says author Elizabeth DeVita-Raeburn with Self magazine. When apologizing to your friend, say something like "I understand that you feel hurt and betrayed by my behavior," or use other words that let her know you've considered her feelings in this situation. Refrain from explaining how her actions may have influenced you to talk about her to another of your friends -- this will undermine your apology and make things worse.

If you want your friend to forgive you, you'll have to ask for it. Once you've empathized with your friend and offered a sincere apology, ask her if she will forgive you. Yoga and psychotherapy practitioner Ashley Turner, M.A., says that you should ask for forgiveness with humility, taking complete ownership for your behavior and how you've hurt your friend. By overtly asking for your friend's forgiveness, you're making it clear that you acknowledge the wrong that you've done.

While it's imperative that you apologize to your friend for talking about her behind her back, this may not be enough -- it's important that you change your behavior so that she sees that you're a different person. Look closely at why you betrayed your friend and ask yourself why you chose to speak negatively of her. Determine to work on being more honest -- with yourself and others. It may take time for your friend to see that you've changed, but she may be more inclined to forgive you if she believes that she can trust your behavior again.

Ultimately, it's your friend who will decide whether or not she wants to forgive you, and while it's difficult to deal with rejection, you will have to accept her decision. Don't try to force your friend to forgive you -- this could upset her and cause forgiveness to take longer. It's difficult to watch a friendship wither away because of a mistake that was made and another person's unwillingness to forgive, but if the two of you share a genuine friendship then sooner or later she'll come back around.