We have 10k customers and issues with PCs well out number Macs, except for how Apple mobile handles video - that really sucks. That's an entirely different conversation and a senior Apple engineer got shitcanned a couple of years ago after saying they bungled mobile video.
I actually think PCs have caught up to Macs in core canilities and in some areas surpassed them. The ability to go to a physical location to address an issie with a Mac and actually get it fixed without an IT department is helpful and the service is just better. Also going from PC to Mac is easy, from Mac to PC isn't quite as easy in my mind.
I think I have 6 Macs I use for testing and just let our development guys test on PCs because it it seems (perception) more complicated.
I know all the stats about SOM with Mac/PC and the various mobile options, but if I had a blank slate I'd chose Macs all the time and it actually pains me to say it because I sit whet damm iPhone, but once you're in the ecosystem your in the ecosystem. I'd take my droid global everyday over the iPhone.
I've only had three Macs age out on me, but they were old and they just couldn't take the OS evolution - I was losses at the time because I didn't want to spend $5k on a computer, but t is what it is.
Long way to say - get her what she wants.