Grab a picture of the two of you that you know (or think) she likes, and have it enlarged. A picture of you kissing or hugging is good, and a wedding picture is great. Place the picture (or poster if you go that big) some place private where she will see it regularly – the inside of the bedroom door or the closet for instance.
I did this a couple of years ago with a wedding picture. We'd gotten married "on the cheap" and the amateur we hired to do pictures botched the processing. But now that we're in the digital era, I was able to find a photoshop expert to recover and restore a couple of key poses, and had one potrait professionally printed for display.