There's a book that is often "assigned" to newlyweds or engaged couples called "The Five Love Languages" that provides some insight into this. I was asked to read it via a church-related program for engaged couples. It's no great scientific and psychological insight into relationships, but I know of a few marriages that it has saved.

The general idea is that there are many (the book outlines 5) ways to express love. If you express love one way and your spouse in another way, you may simply miscommunicate. Your anecdote seems to map perfectly to the "love languages" that the author outlines: you'd be a "words of affirmation" type and she's an "acts of service" type. You need to focus on being helpful because "acts of service" moves the needle for her. She needs to be more verbal because "words of affirmation" move the needle for you. And neither you of you should mistake the behavior of the other as being loveless - it's just not expressed in an effective manner.

Marrying my wife is the smartest thing I've ever done. We have three very young children (all three 5 and under), never get to go out, never get a break, and are taking an absolute ass-kicking between kids getting sick, potty-training, and all the other normal stuff you deal with. And I've never been more content and happier in my life.