Dreaming is all about the symbolism used. Your subconscious mind will use images that are symbolic to try and get messages through to you, that you have been too busy to acknowledge in waking life. Anxieties and desires may show up. Its really a jumble of what your subconscious is thinking while you are asleep. Did you know that although your body sleeps, your mind does not? that is what dreams are, although there is no sensory input from your eyes, ears, fingers etc so the resulting dream can often be jumbled and crazy.
so back to your dream.....what does breathing symbolize for you? some suggestions might be life, nourishment, health, energy. ....is this person having a difficulity you are concerned about ? is there some trouble in their life that they are not adequately dealing with ?
Your subconscious mind will know exactly what the imagery means. There are some images that have commonly held meaning for lots of people, however everyone is different so dream interpretation books that say that water = emotion are not 100% universal, but it is possible to figure out what your dream means if you analyze it and work out your own "subconscious language of symbolism"