Instead of any heavy work out she should do aerobic exercise like walking, light jogging, yoga, swimming.. Exercise should be done within one,s physical ability and increased gradually.
Take fat free
sugar free diet , small frequent mealswith more of fresh vegetables and fruits.
Drink more water.
Let weight loss be gradual, 1 to 2kg. Over 3 to 4 weeks, not drastic.
Get her
thyroid function tests done to exclude hypothyroidism.
Avoid weight loss drugs.
Consult online