its completely normal for people to talk tot heir self, children are taught to talk inside and aloud to their self almost from the moment that they start to form words and realize that those words mean things. even in elementary, jr hi and high school they teach this skill of thinking things out, brain storm, talk your self through something, use your imaginations, hold a dialogue with yourself, those that enter therapy will also recognize these tools of thinking talking to yourself, using self talk and sometimes saying a thought or memory aloud will put it more in perspective. even while reading this I bet if you check in with yourself you will find that you have been keeping a running dialogue with yourself, when you are going about your day take time to check in with whats going on in your thoughts and you may find that you have been having a completely normal conversation with yourself... "I have to remember to do this or that, don't forget this, remember when that happened, I had such a good time with so and so last time I saw them..." its completely normal and how the brain naturally works. we as a species have a thinking brain that never stops having thoughts and dialogues with our self.

going on what you posted my opinion is that your daughter is like my T tells me many times... just having a beautiful conversation with a very important person... herself. Some how she has learned to be comfortable with herself enough to think aloud about her self and her past.