If you do tell her these things they will ring like baby's laughter in her ears. The words will fill her with happiness, warmth, belonging. A few simple words you have spoken to her will burst through the corners of her vibrant smile making her whole face light up with confidence and pride knowing that she is loved by the person she holds so dear.
Whilst yes, these are good things as anyone can imagine but they will only be temporary.You will slip up -nothing personal- we are only human you wouldn't be able to keep to the fiction for long. The first time she may pretend not to notice, for her own benefit of course, telling herself she was overthinking, being stupid and paranoid after all, you do love her, you're not like the others so why would you do that?
After a while it will become clear to her that the other girls are just as special to you as she is. Your girl will argue with you, say she hates you, she doesn't though. She never will. Although she may not hate you, she hates what you have done to her.
Alone at night she will crawl into her bed and wonder why. Why wasn't I good enough? Why was I not enough for him? Maybe he deserves better.
In her bed she will feel the marks you have left on her with your mouth on her neck and your nails on her back. Each glance at them will remind her of what you did together. They will make her feel dirty and worthless. They will fade, in time. The time it takes for them to lift from her skin will be an eternity to her though and she will refresh them each night with a dancer dressed in silver gliding across her skin leaving a flowing red trail behind him.