iPhoto 9.6.1 instead of Photos in MacOS Mojave 10.14.3
I just installed iPhoto 9.6.1 on my wife's (new) 2017 iMac and transferred her iPhoto library from her old Mac. She prefers iPhoto to Photos, and it works fine on her new iMac running Mojave. How do I prevent Photos from "taking over" and, for instance, prevent Photos from opening inadvertently and transforming her iPhoto library to Photos? I understand that Photos is part of the system and should not be deleted, but is there a way to give iPhoto preference over Photos?
iMac Line (2012 and Later)