As milk comes with lots of health risks, inc colon, breast & prostate cancer can a 11yr old get sufficient calcium without milk and how?

Milk. I am not sure who instilled that information in your that milk carries the risks described. Cancer has been attributed to almost any product and exposure in the world but nothing has been proven. Pure milk is not common to be consumed in large quantities at the age of 11, but dairy products such as cottage cheese, buttermilk, butter, sour cream are commonly used and i see no harm in using them.
Many doubts here. Physicians disagree about risks of milk drinking. There's no scientific consensus and there's plenty of bad work / unreproduced results. The major studies i've seen have not supported these claims of risk. The prostate cancer link was popularized as an act of malice against mayor giuliani. In a 2004 nz study, milkless kids have 3x the bone fracture rate. Do your own thinking.