By Paolo Sandoval Mother’s Day can be a surprisingly difficult holiday to nail. Sure, there are the flowers, the chocolates, the odd perfect gift. But if you’ve run through those favorites in recent years, you might be at a loss as to the appropriate present for that certain special lady. But have you considered a fitness wearable? The tracking device industry is no longer a niche market for health nuts — from Samsung’s versatile Galaxy Watch 4 to the streamlined Fitbit Versa 2, the best smartwatches are a functional combination of sleek athletics and useful tracking, all with the standard bel…