My girlfriend who has been separated for more than half a year is celebrating her birthday. Is it necessary for me to send a message to wish her a happy birthday?

No matter how long you are apart from her, I think it is necessary to send her a short message on her birthday. Now that you remember, send it. Maybe one day you forget, you don't have to send it. I think you still have a place for her in your heart. After all, you like it! At the same time, it can make her remember you, so remember her birthday in advance and don't forget to send her a blessing message!