Friends who are competitors probably compete in every area of their lives and find it difficult or impossible to ease up even when it comes to close or best friends. They may compete at work, at school, and even in community affairs. They may be in competition with their spouses or romantic partners, or even with their parents or their children. The Competitor may find this distinctive personality trait hard or impossible to change or eradicate.
You can help the situation, however, by trying to avoid setting up overly competitive situations. For instance, if you share about a success in your personal life or career, especially if you ease into bragging, you may be unwittingly setting off an "I'll show you" reaction.
Helping to heighten the Competitor's awareness about this tendency might help her to deal with this proclivity. If you do want to share something that you think will propel her into a "me too" reaction, you could preface your comments with, "Let me just share something with you without it having anything to do with you, okay?"
The onus for changing the Competitor's behavior, however, is on her; developing a better self-image will diminish her need to compete with everything you say or do.
If you wish to stay friends with the Competitor, you may have to be willing to listen to her brags and boasts far more often than you can share your own.
(source: Jan Yager / photo copied from another website)