From the Business software section at TUCOWS, three freeware alternative suites, including Sun's redoubtable OpenOffice. I have looked at EasyOffice before; it is somewhat "cartoony", but would be an excellent introduction for your mother-in-law:
EasyOffice with PDF Filter 5.95
This office suite is compatible with PDF, MS-Word and Excel files. The word processor supports RTF, DOC, HTML and PDF files.
EasySpeaker is an English-voice reader. EasySpreadsheet reads and writes Excel XLS files. EasyPresentation has special effects, animation, clipart and sound effects. EasyContactManager integrates automatically with EasyWord, EasyCalendar, EasyZip which allows file compression and decompression in both easy and advanced modes. EasySpeller and EasyDictionary is a full reference dictionary. EasyBookkeeper performs classical double-entry bookkeeping. Easybookkeeper supports double-entry bookkeeping.
The built-in contact manager supports hotlists, mass e-mailing and form letters. There is also an image viewer, a database and a calculator.
602PC SUITE 4.0
This office suite is compatibile with Microsoft Office. It includes a word processor, a spreadsheet, a photo editor and a digital photo organizer.
The word processor uses the DOC file format, and it also opens TXT, RTF and HTML files.
The Excel-compatible spreadsheet has more than 150 functions. It can open CSV and DBF files, and you can use it to balance your checkbook, calculate loan payments or export tables to HTML. Data can be presented in 12 different two and 3D graph types with the Graph Wizard. As a stand-alone application, the spreadsheet can be used to insert tables directly into 602Text documents.
A photo editor and organizer rounds out the package. You can create digital photo albums and share photos on the Web with the upload function.
With this office suite, you can create dynamic documents, analyze data, design eye-catching presentations, and produce dramatic illustrations.
You can continue to use your old Microsoft Office files without any problems, and this suite even lets you exchange files with people still using Microsoft Office.