Aww so sorry she is dealing with this. I wish her the best. Maybe cozy items like a soft blanket, warm socks, or a robe. Snacks that are generally well tolerated, like ginger candies, crackers, or herbal teas. Make sure to check if they’re suitable for her current condition. If she’s up for it, a gentle massage or a spa day might be relaxing and uplifting for her. If she enjoys reading, light novels, inspiring books, or even audiobooks can provide some distraction. A subscription to a streaming service can also offer her some entertainment. If she's into writing or art, a beautiful journal or some art supplies can be a creative outlet for her. If she struggles to prepare meals, consider a subscription to a meal delivery service that offers ready-to-eat meals, or healthy options designed for those going through treatment. Put together a small scrapbook or photo album of memories you shared, along with notes from other friends or family who care for her.
If you’re in the USA try this website or something similar they offer special dietary foods delivered and other items. https://sendameal.com/how-it-works/
There’s also this meal delivery in the USA that’s made especially for those with illnesses, post surgery, or similar situations. https://www.magickitchen.com/our-story.html
Also see if there’s any non-profit organizations that assist with meals, comfort items and/or any medical supplies she might need/want.
Aww no poor her. Heating pad. Ginger tea for sickness. Hot water bottle. Fluffy socks. Blanket with arm holes. Something funny like a rude book? I still think food voucher is a good idea though maybe suggest a place on there where she can order plain rice and chicken soup if that is where she's at or maybe there's some other kind of meal delivery service where they serve up more basic mild flavoured meals which are easier to stomach?