I own and operate a coffe shop. Yes I know how to make very good espresso drinks. I make a living with my recipes though
I would suggest doing away with the seasalt as salt does not taste good in ANY espresso drink.
IF she absolutely must salt it though I would suggest getting a blender and making yourself a frozen latte using frozen yogurt and espresso. The ice creams sweetness will cover up the saltyness. OR you could make a very strong mocha. that might do it.