Looking for a NAS box for Mom

Following your last post, if speed is not an issue, and it does not seem to be, then consider the NV+. From Newegg, it is $330 with shipping vs $190 for a second Duo. You can shut down you Duo, remove the drives, insert them into the NV+ and when you boot it should power right up with only an IP address change marking the difference. The interface is the same, and the performance is the same. You would gain the display panel on the front and the future expansion into the other two bays if you ever need it. Whether that is worth the extra money, is up to you. Obviously, the most economical plan at this point is to simply have your mom buy a new Duo and two drives, and you set it up for her.

If she is using Windows, you can map the Backup share in her Duo to a drive letter and almost any backup software package will back up to a drive letter.

I agree about the display panel, it is one reason I very rarely recommend the 2 bay units. But, they are so small there just isn't enough room for one.