It's better to wait. Just becoming
pregnant is not enough..the goal is to deliver a healthy baby at term. So,as your friend is quite young, it's better that she allows her body to heal fully from the aftermath of the miscarriage..and give it some time before trying again. To allow a gap of 3-4months is beneficial.
Next Steps
The patient should start on prenatal vitamins, and get herself checked by her nearest Gynaecologist to rule out pallor,
thyroid abnormalities,etc.