Having a repeater won't guarantee you will be able to talk. Both your radio and the handheld your wife uses have to be able to reach the repeater. The repeater itself has to be operational during whatever emergency that is causing your wife to use it rather than a cell phone or regular landline phone. Just as a figure-of-merit, you are looking at a cost of about $1500 to install the repeater, power and antenna. It can be done for less, but as you stated it is for emergencies, you'll want a repurposed commercial unit over a low end unit manufactured for casual use.