Is her husband raping her or abusing her by having sex with her when she is not in the mood?
Aside from his physically harming her by forcing himself upon her no he is NOT abusing his wife from a Biblical perspective. Even if he did physically force himself upon her – it is IMPOSSIBLE Biblically speaking for a man to rape his wife. Abuse? Yes. Rape? No. For a larger discussion of the Biblical impossibility of marital rape I refer you again to my post “Is a husband selfish for having sex with his wife when she is not in the mood”.
If he convinces her to yield her body to him, then no sin has been committed on his part. But it is very possible that even if she yields to him – there is still sin on her part. If she acts disgusted by him and acts like he has no right to have sex with her – then the sin lies squarely in her court. She needs to eliminate the terms “rape” and “molester” from her vocabulary regarding her husband’s sexual advances toward her.