Her fish died, what do I say?

Jurckie Backhart

So my daughter just turned 5 last week. She is already concerned about dying and I'm not really sure why but sometimes shell just randomly say "I never wanna die I would miss you so much". Well for her birthday we bought her a fish and it died. I want to tell her the truth because I want to have good communication with her but im also worried this will further her worries surrounding death. Any advice?