AS regard body odor, first to consider is hygiene - does you daughter take a regular shower/bath?; how often does she change her clothing?;  does she repeat wearing her clothes even without washing? These are some points to consider. Also you need to look into her diet - some foods have strong/bad smell such as too much garlic, onion and other spices.  

Regarding her clothes, smell them before and after washing. If after washing there's still bad odor especially in the armpit area, throw it away because even if she has  already taken a shower/bath, she will still smell bad. If there would be a problem re this, try rinsing her clothes in baking soda solution - in a pail/basin of water put 1 tsp baking soda -. This might help. 

Also, choice of materials for her clothes could help. Choose cotton and other fabric that allow the body to breathe; avoid synthetic materials.  

Baking soda is also a good deodorant. Apply on armpits after every shower/bath. Armpits should be thoroughly dry before applying.