Money matters between couples are always very touchy. Or more to the point, when should you offer to become financially involved with the person you are dating? If her car breaks down, should you offer to pay for the repairs or let her deal with it? If her lawn mower dies should you offer to buy her a new one?
I personally think it is unreasonable for you to be financially committed to anyone to whom you are not legally committed. But, that is up to each individual.