I don't know if something like this would work for you...but find a picture frame like you want and have a mirror cut to fit it. You could even paint the frame to suit your secretary.

Try homegoods.com - same parent company as TJ's. Super good stuff, but you have to go look, 'cause it changes all the time. It's one of those "better to buy & take it back, than to expect it to be there tomorrow".
On the East coast, we have craft stores called Michaels. An option.... good luck!

You might also try thrift or consignment stores. Silly as it sounds, they often have different types of mirrors on the cheap. Get the right size and like Grandmaof3 says, you can always change the frame for it.

this might not be right for your chest...but it's 18"- $132 at Linens and things and you can use one of their coupons for more $$ off.

How small is small? I have this 14' one from Ballard and love it...

Thanks for the ideas, everyone. I hadn't thought of the picture frame angle. And I have tried HomeGoods too. No luck. But as you say, always new stuff coming in and I will keep checking back. I'll also keep an eye out if I hit any thrift stores too. I never seem to think of those places, but they do have some good stuff, and you never know what you'll find.

Regina, that's funny! I actually bought that Ballard Designs mirror about a week ago and it was the right price, size, and I liked the look...but it came with black spots all throughout the mirror. I've not returned it to them yet. It would've been perfect without those spots.

Olychick, I do like the LNT mirror you posted. It is a little more than I want to spend, but I will keep it in mind. It's very pretty.

Tammy- I have that mirror from Ballards too, and I just wanted to say that those spots are intentional. I never paid attention to the description but those spots are actually "antiquing". At first I wasn't happy with them, but they are so subtle I hardly notice them now.

Just wanted you to know there isn't anything wrong with the mirror... they just don't do a good enough job of describing it!

Go to a framing shop or a hobby store where they do custom framing, and pick out the frame material you want. They can cut to any size and dimension. Then take it and have a piece of mirror installed (very inexpensive).

My only additional suggestion on this is to make up a paper template and hang it on the wall above the cabinet, to be sure of the size you want before you invest the money.

Makeithome, hmmm...I didn't know that. Maybe I'll take another look at it as I haven't returned it yet.