Snow tyres is what she needs, not 4×4,
a 4×4 softroader mum truck on 20″ bling alloys and tyres as wide as a Countach from a few years back will be no use in the snow at all.
In fact they will be a lot worse once you have lost traction because they are generally much heavier and have more momentum / inertia.
Snow tyres on the other hand, just work.
You will still get stuck however behind all the other people who thought they needed a 4×4 and still cant drive for toffee in snow and ice.
Remember, the only thing connecting you to the ground are the 4 tiny contact patches, if they don’t grip then 4wd is not going to help at all.