Option 2: You can send 52.00 yuan to your girlfriend to show "I love you".
Option 3: You can send 13. 14 yuan to your girlfriend, and 13. 14 means "lifelong". Or you can send a WeChat red of 52.00 yuan first, and then send a 13. 14 yuan to your girlfriend, which means "I love you all my life"! But the above are all references. The specific situation should also be chosen according to your own situation. Good luck.