you should try resetting the SMC on your Mac.
https://support.apple.com/en-ca/HT201295
Shutdown your MacBook Air / MacBook Pro
Connect the power adapter to the Mac
On the MacBook / Pro’s keyboard, hold down the Shift+Control+Option keys and the Power button at the same time
Release all keys and the power button at the same time – the little light on the MagSafe adapter may change colors briefly to indicate the SMC has reset
Boot your Mac as usual
As for a new computer, I'd say it depends a lot on preference, especially with pc's, there's a lot of selection. Take your wife to Chinook and check out the different pcs at the windows store and compare them to the Macs at the apple store.