I usually record onto DVD-RW discs in case of any problems.
If everything is OK then you can copy the DVD-RW onto a DVD-R disc if necessary and then erase the original RW and use again.
That way you don't get any coasters.
Some PCs are not happy with a DVD-RW recorded on another computer.
It may be more to do with the program you are using to burn the discs, it could also be the file format, she may not have the correct codecs on her PC to view the files.
.. lol .. Is that right Marty?! Where did you get that from?
It doesn't work like that.
Use -R
She will need MPEG-2 spiltter and decoder ... and AC3 filter installing on PC .. unless she has a DVD program installed (like WinDVD or similar)
Alternatively she can use VLC player or Classic Media Player to play DVD.