There is certainly no reason at all to not give her whatever she'll eat at this point; I've even received this as advice from a veterinarian when dealing with a cat nearing end of life. At this point, any harm that would be done from the lack of nutritional completeness likely will take longer to manifest than she has left, so it's better to let her have at least something she likes (so she doesn't starve) and keeping the last of your time together as pleasant as possible for her, than to try to force her to eat something she doesn't want.
If you are concerned, many varieties of Temptations branded cat treats are nutritionally complete, and tend to be highly appealing to most cats, but ultimately, whatever she wants to eat--whether that be her favorite treats, people food, dog food, etc.--is ultimately okay. You can certainly speak to your vet to confirm, but they'll likely tell you the same thing--just let her eat whatever she wants now, and make the best of her last days.