>>> any difficulty adding her Windows based computer to the network?
What do you mean by adding to the network:
- linking to your Linux computers for File/Printer sharing?
- connecting to your router for internet access?
Connecting to your router won't be a problem as routers are "platform independent", using TCP/IP to connect regardless of operating system.
As far as File/Printer sharing is concerned, Windows should be straightforward and find whatever network shares you've set up. (I've used Linux to access Windows folders and I use Windows to access a Mac, but I haven't actually used Windows to access Linux.)