Thought I would write out a short list of my correspondences of milk in magic

Life: Milk is used to sustain life as soon as it happens. You can use milk to symbolize your life or someone else. Great additive to healing spells, especially for those with life threatening illness

Healing: Milk not only gives life but it strengthens it. It gives immune resistance and has much of the needed vitamins needed to sustain life.

Isis: Milk can be used in worship of the Goddess Isis.

Feminine energy: Using milk is a powerful way to represent a feminine energy

Adaptability: Milk can be used in so many different ways. I use it in spells that deal with change, and attempting to deal with change