there is really no set amount but a pre-teen girl does need plenty of calcium phosphorous protein and all of those nutrients found in milk and milk products. these minerals vitamins and protein can be found in many other food sources if she eats them. if she was allergic to milk she wouldn't be drinking any so these other non-milk sources would be essential to her. if she eats cheese yogurt or even ice cream she is getting milk in another form so the bottom line is: milk is a good healthy source of many nutrients but an exact amount cannot be determined unless we knew what she was eating. personally i like milk but humans are the only mammals on this planet that continue to drink milk after we have been weaned. we like it but we don't necessarily need it if we have a good diet.
how much mild should a 12 year old girl drink per day