Happy new month for your girlfriend
Here's a message you can send to your girlfriend:
"Happy new month, love! I hope this month brings us even closer together and fills your life with joy, happiness, and all your favorite things. You deserve it all and so much more. I'm grateful to have you by my side and can't wait to see what this new month brings for us. Love you!"
Feel free to modify it to fit your personal style and relationship!