Unless she's a veteran burner, I would
not go with the Leyden. Ask your dealer to explain the difference in the secondary burn system of the two stoves, and ask lots of questions regarding how easy/difficult it is to establish a secondary(smoke) burn in each one.
I have a Woodstock soapstone stove, and I do think it would be a nice fit for a smallish, well insulated home. The only drawback is that they are mail-order, so you would have to find a local installer. Your local dealer might use an independent installer.
Always good advice. Wood vendors almost never sell wood that is as dry as modern stoves need. If you don't already have dry wood for MIL, you might as well forget about burning this season and take your time shopping for a stove. Stoves will be cheaper in another month or two anyhow.