Hi Lisa,
Like Thunder Bow, I see characters in the dream as representing parts of yourself. The "you" in the in dream is your ego, your conscious awareness of yourself and your conscious idea of your personality.

You say that an orca is both amazing and terrifying, so you have mixed emotions about them. And in the dreams, as you say, there is a mixed experience. An anticipation followed by a let down. The orca may represent a powerful wild animal energy within yourself, a part of yourself that feels very powerful and alive, yet is scary.

What significant events are going on in your life right now? You say that you haven't dreamed of orcas before, so this may mark some significant event or feelings.

The children may represent the childlike part of yourself.

In the first and third dreams you hang back and don't approach the orcas. In the third dream the children approach the orca, encouraged by the trainers. The childlike part of yourself may be more drawn to the orcas or trust them more, while you fear for their safety. The children are more naive in a way, accepting the instructions of the trainer and not fearing for their safety, although they seem to come into danger.

In the second dream, the trainer is cold and clinical when you are concerned for the well-being of the orca. What are your associations to the CEO of Seaworld? Does he relate to your feelings about whales in captivity? What are your associations to Ugg boots? The trainer when he is cold and uncaring may represent some cold and clinical part of yourself. (We all have that.)

Mike