Before you go digging into Kstars/INDI code I would first check that your wife's computer has at least 4GB memory or preferably 8GB. You may even have failing memory issues. Also try upgrading from HDD to SSD - this is well worthwhile and is very easy do do (check out www.macsales.com/ for compatible SSD and additional memory).
I have a 2012 MBA with 8GB memory and a 50 0GB SSD. Works like a charm with all sorts of development stuff installed - Xcode, Macports, XAMPP, VirtualBox (often running Win 7/10 or various Linux versions), etc. I have set up an INDI server on my spare PI yet, but its on my list!