Hi @mandic, as @colleenyoung explained in a previous reply, platelet fluctuation can be a side effect of your sister’s sickle cell anemia. While her platelets are lower than the ‘norm’ of 150,000 to 450,000, at 72,000 she still isn’t in a dangerous zone. If the count gets critically low, her doctor may suggest a platelet transfusion, though that generally doesn’t happen until the level gets below 10,000.

There are some natural, nutritional ways to help boost platelet counts but I’m not sure how helpful it may be for your sister because this may be an ongoing situation for her. Here’s is a link to to the Very Well Health website.
https://www.verywellhealth.com/how-to-increase-your-platelet-count-5190448
Before eating certain foods like Papaya, oranges or grapefruit, it would be best for your sister to speak with her doctor or pharmacist first. There are some fruits which will interfere with medications.

That leads me to this question…is your sister on any medications or does she have blood transfusions for her sickle cell anemia?