Some women’s libido goes down from the stress of seeing a lot of chores needing to be taken care of. Doing those chores reduced the stress. Going further and doing what is normally their share of housework can be an act of affection.
It’s also noted in a study of women asked to rate a number of pictures of men on various factors including attractiveness and reliability. When they are also asked for dating preferences, as the age range went up, the prioritization on reliability ratings also went up. Doing chores is reliable AF.
More to the point, she’s already told you she likes it. Just believe her.