My limited experience with WiFi repeaters has been a failure.
Antenna(s) with signal gain on the router could be a solution. Directional antennas pointed at your wife's location might help, if the other WiFi user(s) of the router presently get strong signals.
Is there any chance that you can locate the router in one of the intermediate rooms? That would mean fewer walls to penetrate.
If she already gets spotty performance (rather than none at all), only a modest increase in signal strength may be enough. Digital signals tend to be very good or very bad, with little in between.
Can she move the antenna on her equipment around?
seacue