That's the problem. TextEdit, Preview do use versions and there's no consistency.
If she needs to get work done now. Really just install MS Office in the Windows version on bootcamp and/or a virtual machine. One should bother with all the new stuff when there is time.
Getting used to iWorks, OpenOffice won't happen in a day if you are used to the newer MS Office. MS Office for Mac is as mentioned crap. That is such crappy slow buggy software with a strange half backed UI concept, I for one don't understand how they could ever release that. If it was some first beta but it is now 2011 and 2008 was bad already. 2011 is better but still really poor.
In a VM Windows office works well and as you'd expect. Obviously it doesn't behave like an OSX app. There is no consistency.
Me I use textedit, office 2011 or openoffice when I don't need much. For big documents after two years I still launch Windows. Office 2011 powerpoint is okay but Excel and Word suck.
Mac and Office just don't play well in the long run get used to the alternatives or live with crappy Office 2011.
I never bothered with iWork myself. I tried it a few times but too often ran into limitations that drove me back to MS Office until I just quit trying. IMO Open Office is better as it mostly different in the User Interface and less in functionality than MS Office.
iWork has great integration with OSX but that is imo its only real strong point. Aside from that integration Apple is not much into updating iWorks. Is mostly small updates and fixes.
Textedit is also weird and a little inconvenient since ML. I don't really get much use out of it anymore. Used it for small stuff now I switched completely to editors and don't ever touch textedit.
PS: If you like consistency you might get along better with iWork and Pages than me. One thing I also greatly dislike about it is that it is so different that it has quite a learning curve and I hate getting locked in into OSX too much. I try to rely on multiplatform software where ever possible because I don't want to be so deep in the Apple stuff that getting out of it would require too much work. I also needed to do much collaborative work and nobody I know uses iWork so it is really a complete fail on that part. You can open docs, docx but don't imagine you can actually work with Office users on the same document. It is a pain.
If it is just for you and only you it is probably not so bad.
Me I am very unhappy with where Lion and ML is going even though I am a big fan of Snow Leopard and can deal with ML deficiencies. Still I don't expect my next computer to be an Apple again and are thus reluctant to bind myself to a plattform so strongly that I cannot simply switch back to Windows if I don't like the next hardware iteration or the price tag or the next OSX changes.
For the same reason I don't buy AppleTVs and all kinds of Apple stuff. Closed environments suck, are inflexible and expensive if you want to change at some point. There is lots of Multiplattform software and many is quite good, also stuff like iphoto/Mail is so simple there is no switching cost included. Office isn't if you know how to use many features imo.
I mean to say completely converting might not be a good plan.
