If I were making this, I would stick to the pink florals and plain fabrics, because that color is what the friend asked for. The florals will give a vintage look rather than childish. Even a white/off white background, or light print would not be out of place.
Actually, my friend does not know that I am making her the throw. But I also agree that because she likes pink, the pink florals would be best to start with. Plain fabrics too can accentuate the florals, and could be shown in different shades of pink, as someone suggested to make it a bit more adult. I have got same great ideas to ponder because all of you have been so very helpful. Sometimes one goes over and over in one's mind and cannot decide. I like to talk to others to get a fresh or even brand new perspective. Thank you everyone.