She will learn to love the room, but I suspect that you are right about her needing more decorations. :)
If you have the money, buy some fast-growing plants. They are an investment, as they will double in size very quickly, allowing you to trim them, plant the offcuts and have a second plant for free. (Then a third plant, and a fourth...). She will also like these more than plastic decorations, I think. :) Some good plants to do this with are lacefern, ambulia, cabomba, anacharis and hornwort. I ended up having to remove my lacefern from my 16 gallon in the end because it was growing so fast I couldn't keep up with the trimming!
Another low-budget solution is to buy some fake flowers from a dollar shop. Remove any wire from the plants and you have your own, cheap, silk plants.