Use powerbook tiger cds to update

hypothetically of course, could i use the cds i get with my new powerbook to upgrade my moms g4 ibook? would the install include an option to keep all the data on the hd? and just install the os

I can not say for sure. I have read in some place, that you can not and in other places you can. The major problem here is an ethics situation. You have a one user license of the software that will come with your powerbook and you will be using that license, when you use your powerbook. As for the original question, I believe that Apple sent out a specific set of disks per hardware. The disks may work on the laptop but not on G5 line.

Some one may come along and make it more clear for you.