My little sis who is 5 years old is feeling stressed due to this pendamic covid - 19 what should i do?

Stress in kids: Children are often highly influenced by the emotions of those around them. (especially adults) Anxiety in the Adults is noted and internalized by the child. Work on healthy habits such as daily exercise (walking outdoors, playing in outdoor spaces), listening to music, playing games and other normal activities that she enjoys. Reassure her that this shall pass and make fun plans for the future.

COVID 19 pandemic: I agree with Dr. Kratzberg, The ways that you and your family express your emotions and thoughts about the pandemic will significantly impact her, even if she doesn't really understand what is going on. You can let her know that things are being done to improve the situation. Make sure that she & you have enjoyable activities so you aren't just focused on negatives.