You are too chauvinistic. You need to comfort a girl immediately when she is angry. In fact, girls are not that difficult to comfort. They may be angry just because they want you to comfort them. Since her birthday is coming soon, choose an exquisite birthday gift and spend an unforgettable birthday with her. I believe that your relationship will be deeper.
The recommended gift for your girlfriend is a cartoon bouquet of roses. Every girl likes roses. It is very beautiful with a cute little bear. Of course, you must express your love to her. After the gift is delivered, sweet words are also indispensable.
Handmade chocolate is also good. It is delicious and beautiful. You can also write what you want to say, which will definitely surprise her.
Or a couple doll made with photos of the two of you, which is very funny and commemorative.
The gift is secondary. The most important thing is to find a way to make her happy. Don't make your beloved girlfriend unhappy because of face problems! I wish you success!