Sister-in-law is seriously ill and is now in the hospital. How can I comfort my brother so that he doesn't worry?

Tell him that my sister-in-law is broken now, but you can't indulge in sadness. You should cheer up. What would you two do if you fell, too? And do you want my sister-in-law to wake up and see that you are thin? She will definitely feel distressed and will not recover well for her (in fact, I am talkative ...)