Thanks for all the advice guys. I don't really hate Macs. I just don't know them and I fear the unknown.

They are beautifully designed and operate very well. I'm just committed to PC.
I guess I should better explain the issue:
She is uploading to a host. I understand the clog is not the "b" versus "g" thing but the problem as we have seen it is that when was trying to upload some files to the host site it was taking forever. She tried the same files on my wired-in PC and it zipped along lickety split. Everything seems to be faster, according to her. Her main problem is the slow uploads from her Mac as compared to on my wired PC. She does also complain about the slow browsing. Will a "g" card help in general?
Juan: You are correct that her Mac is older. It's about 3 or 4 years old so Airport Extreme is out.