Making your girlfriend happy after a fight requires patience, sincerity and understanding of her. Here are some suggestions that may help reconcile and keep your girlfriend happy:

1. Calm down: Give each other some time and space to calm down and avoid saying more hurtful things in the heat of the moment.

2. Active communication: After your mood stabilizes, take the initiative to talk to her and express your willingness to solve the problem.

3. Admit your mistake: If it was your mistake, apologize sincerely. A sincere apology can defuse a tense situation.

4. Listen to her feelings: Let her express her feelings and listen carefully instead of defending, which will make her feel respected and understood.

5. Express your feelings: Use "I" statements (such as "I feel...when you...") to express your feelings instead of blaming the other person.

6. Get to the root of the problem: Discuss the root causes of the argument and work together to find ways to resolve the issue.

7. Propose solutions: Propose specific improvements, such as how to avoid similar arguments in the future.

8. Make changes: Commit and take action to change, and let her see your efforts.

9. Small surprises: Give her some small surprises based on her preferences, such as her favorite flowers, a meal she loves, or a handwritten love letter.

10. Spend quality time together: Plan some activities that both of you enjoy, such as watching a movie, taking a walk, or cooking together. Sharing quality time can help repair the relationship.

11. Keep a sense of humor: A dose of humor can relieve tension when appropriate, but make sure you are not making fun of her or making light of the issue.

12. Continue to care: Even after an argument, continue to show your care and love for her.

Every couple’s dynamic is different, so what works best may vary from person to person. It is important to show that you are sincere and willing to work hard for the relationship. Remember, communication is the most important part of a relationship, and with effective communication, most problems can be solved.