I can access the S3Store just fine from my computer. My wife can't!

Ask her to login on your computer. It's the fastest way to find out whether the problem is her account or her system, and that way, she won't have to delete her cookies or browser history. A private window won't use existing cached data.

Also, now's a great time to start collecting those passwords. You never know when you might have to wipe your system, or it'll get wiped by accident, and it would be awful to lose access to all those sites.