Worried about adult DD health

[BigSilly]

Dd1 is 23 and is always ill she literally has a new cold every week. She is a primary teacher and her job is very stressful, and people ve always said this is the reason, but it started way before this. She is very pale with dark eye circles and red itchy skin and trequently has allergy

(Sorry pressed) send too, soon
Terrific Night sweats, and exhaustion. She goes to the gym a lot and eats fairly well but she has put on loads of weight
After the first round of blood tests the doctor has ordered a lot more, many of which seem to be related to her bones. What are they suspecting?