here is something i did not notice in the other responses. i belive you stated that she moved into your home when you got married………herein might lie the problem……your home! has she done any redecorating? has the apt been turned over for a womans touch? she may feel as if this is your turf and that could be turning her off from caring about taking care of the home (as you call it).
imagine if you will , that she comes into a fully furnished home when the two of you got married. nothing for her to decorate, to give her own flavor to. all ready made. perhaps that makes her feel left out.
think about it, i might have hit the nail on the head.
if i am am right, then you can work on some minor redecorating in order to make her feel like she is part of the place too. usually a newlywed couple put an apartment together TOGETHER . that could give her more feeling for the place.
good luck!