I've only stayed at the Llao Llao, so can't recommend any other hotels, but note that it is somewhat isolated and not within walking distance of anything else, so if your mother wants to walk around Bariloche, she is better off staying somewhere closer to the center of town. Llao Llao is worth a visit, but the standard rooms are very small and not IMHO worth the price for a one night stay.

I second the vote for Rincon Patagonia. The concierge at the Llao Llao sent us there. Amazing restaurant - one of the best we ate at during our 10 day trip.