Everyone loves receiving cute good night messages from a loved one before they go to sleep. It doesn’t have to be a long good night message, it could just be a short text wishing them a “peaceful sleep”, or saying “I love you” before they go to sleep.
It’s more about the fact that you were thinking about them, and made the effort to send them some cute good night messages. So take a moment, and send some good night messages for girlfriend, she’ll appreciate it!