Start by avoiding all Estrogenic compounds.

Avoid commercial factory-farmed meat products as they pump them full of hormones and Antibiotics , avoid all plastics because they have compounds that mimic Estrogen.

Even commercial laundry detergents are a culprit, as they act like Estrogenic compounds when they touch the body.

Also never drink sink water, distilled is best or something like a Berkey Water Filter and even a filter you can install on your taps or household filtering system which removes Fluoride along with Pharmaceuticals which are found in tap water.

Taking Iodine is a good start as well, Lugols Iodine is a good form of Iodine...

Your daughter should be weaned off milk by now. She should not be drinking human milk or milk from any other species including cow milk. Cows are injected with estrogenic hormones and chemicals to give the cow huge utters (huge breasts) to keep the cow lactating ("pregnant") and these chemicals end up in the milk which is what your daughter drinks. Cows are 1500 lbs, your daughter 60 lbs, do the math. Why do young females develop early nowadays and young males are underdeveloped? Dairy products like cow milk, and other xeno-estrogens like BPA plastics, sun tan lotion, liquid soaps, and food like soy, soy baby formula, flax seed...

Not to mention the puss and Antibiotics and other nasty stuff that ends up in the cow milk bought from the store. This also goes for all dairy like cheese and yogurt etc...

The massive amount of sexua| content in tv, media, advertising and entertainment today also sexualizes young girls and boys at an earlier age which probably contributes to "developing" early so mentally they are being forced into sexuality as the body follows the mind to some extent.