I think bilingual children have a "natural" capacity to take the best of both worlds. Language for them is plastic and they can mold it to their needs with disconcerting ease. Their bilingualism makes them more "aware" of language.

My French kids (I'm Irish), coined the French verb "flusher" because the French equivalent of the English verb "to flush" (the toilet) was too much of a mouthful!!

Kids are also "natural" translators. I am a professional translator and am always in awe of my kids who manage, without thinking, to get beyond the words, and translate, ideas, concepts and the real meaning of something.