Yes when the cot is in good condition. You can give the mattress a new cover from material you can wipe down and desinfect. Sheets and blankets you can wash. Think about hospital beds, mattresses, pillows and blankets; they’re thoroughly cleaned and reused for many patients.

Yes, if I knew the family member well. In fact, my cot and mattress was from my cousin. I just wipe it down top to bottom and re-wash the bed sheet.