Hmm...I can see how the placement is a problem. Even I wouldn't want to put my speakers on stands in front of a couple of windows.
I suppose you could move the sitting position a bit closer, but 5' away is awfully darn close.
How do they sound where you are now? If it's not bad, it seems you may have to live with it, or come up with a completely radical room change. i.e, move the system in another room all together, or rearrange the entire room they're in now.
I do understand your wife's concerns though. Your setup does look like it "fits" perfectly right where it is. Unfortunately that "fit" is cosmentic, not accoustic.
Good Luck!