In moderation it will be fine, honestly I don’t have a problem with normal milk in small amounts. Normally just in my coffee and an occasional glass, but I do eat lots of yogurt and other probiotics.
Something to remember about this illness is that everything the body consumes is converted into sugar which the candida can feed on. The goal is to consume foods that break down slower giving your body time to use these sugars before the candida. But anything you do not use for fuel will likely be used for fuel by the candida. So avoid over eating anything while staying active, dieting and you should be doing really well. Back to your question, coconut milk should be fine and I believe is the recommended milk for us to drink.