some ideas:

https://www.amazon.com/Womens-Floral-Sleeve-Chiffon-Cardigan/dp/B07J5K2FX5/

https://www.amazon.com/Bluetime-Sleeve-Sweaters-Lightweight-Cardigan/dp/B089GDT44S/

https://www.amazon.com/Omoone-Womens-Sleeve-Cardigan-0774-Light/

Could layer on a super lightweight and loose shirt: https://wearpact.com/women/apparel/tops%20&%20shirts/clearance%20the%20coastal%20daily%20top/wa1-wgz-fra

If you just need coverage, not support, you could wear something like https://www.target.com/p/women-s-slim-fit-cropped-tiny-tank-top-wild-fable/-/A-85727203 under any shirt.

If you're okay with something sheer, https://www.amazon.com/Kate-Kasin-Dresses-Cardigans-Lightweit/dp/B096LTJ74Q

You can wrap a lightweight soft shawl over your shoulders, or something like https://www.amazon.com/MissShorthair-Lightweight-Knitted-Sweater-Cardigan/dp/B085RHY3HQ