Try to eat meals together. I did this with my grandfather. I made a pretty tray a tiny vase of fresh flowers, just a few stems, and he seemed to eat better when he had company in doing so instead of the hospice nurse repeating herself to him to eat. Good wishes to you.
I would create a little platter of snacks, like cheese, crackers, grapes, etc. (assuming the patient can feed themselves), then have a good conversation about how things were when she was younger, maybe look at pictures, or put a good classic movie in that she may like. Then maybe she'll start picking, once she is relaxed and feeling more casual.
Anything within their diet that is sweet like apple sauce is usually appetizing. My mom devoured jelly rolls, but stay w/in the diet and like they said, eat with them. Nobody likes to eat alone. Thank you for being kind and thoughtful.