If, for whatever reason, you are not prepared and you end up needing more food, water, clothing......
you are going to hear about it the whole hike. A little more food, water and clothing layers are not going to slow you down. Moreover, they will reassure her and let her know you are looking out for her.
Nothing worse than being "that" guy who isn't prepared. Those experiences will haunt you for a long time. Women have very, very long memories.