You have no idea what you're talking about. It's not "too much", and if she thinks it is, she's psycho. You've never had a girlfriend, and have no idea what it's like to be in a real relationship. It won't make the relationship more "soild", sure, but I don't think that's what he's going for. I think he just wants to do something nice to show that he appreciates the girl.
As for actual inspiration, I'm not sure, as I'm not really the best writer in the world. If you wanna write a poem about her, just think about her. Write about her, or about the two of you.