Always prefer flowers to chocolates and wine to flowers.
A bottle of a good Portuguese red wine will always be much appreciated, both by a woman or a man. Don’t be offended if the bottle is not opened at diner because most surely the hostess has already provided the right wine for the food to be served, which might have been cooked using the same wine that will be served for diner.
If you really want to enchant the lady in the house, bring a small live plant.
Special note: Quinta dos Quatro Ventos and Quinta de Chocapalha are two Portuguese wine brands that can be found at Brandimport Warehouse Club.