Looks like there is hormonal disturbances due to weight gain,and as she is also heading towards puberty, we need to rule out all her nutrional defeciencies
Next Steps
connect with a general physician for advise on diagnostic tests,based on the defeciency status I can plan a customized diet plan with subsequent follow-ups .
Health Tips
Restrict junk and processed,ready to eat foods
Make her select healthy food choices also encourage her to do meal preparation every now and then .
Help her in finding a physical activity appropriate depending on her sustenance levels