First, she should filter the mixture using a filter funnel and filter paper to remove the sand. Then, she should distill the remaining solution, using a bunsen burner, a distillation column and a condensing cylinder, leaving the salt to depoisit, and she should collect the water exiting the condensing cylinder in a beaker. To check that the water is pure, she should use a thermometer to show that the boiling point of the liquid is exactly 100 degrees Celsius.