I agree. While it's not the most efficient method of carry, LUCC does give you certain options. More options concerning situations where your life may be at risk is always better. And the gun could always be part of a get home bag/kit, too. Doesn't necessarily HAVE to be just for the purposes of immediate self-defense. Again, more options.
I think the point others are driving at is your mother shouldn't rely on LUCC as her primary means of self-defense. It's too slow for that purpose. Make sure she realizes that its a measure of absolute last resort ONLY if she has time, and even then ONLY if she has nowhere left to hide or run.