Normally, she's going to do internet, messages, stuff she does on her phone. She doesn't do photography or any heavy software use. So if the iMac integrates easily with her iPhone, that would be good. I use my Windows desktop for storing all our personal files, word documents, scans of financial and medical stuff, etc as well as any pdf documents. Of course, I was hoping to network them to her new machine so she can look for those files from her machine and create scanned files of new documents on her machine that she could save in my machine. That would be easy if both machines were windows. But if we get her an Apple, well, I'm seeing all sorts of problems and limitations.
How would Dropbox work? Is there a fee? Do you have to download the whole file if you add a couple of new files.