Princess M: New Habits

Princess M has developed a quirky new habit.  As she is talking through her thoughts, often times out loud to herself, I've noticed some linguistic patterns.  She will talk for a minute and then when she comes to her conclusion she says "so", then launches into what comes next.  It amazes me because she is using the word correctly, but for the life of me I cannot figure out where she is getting it.  There isn't anyone that she comes in regular contact with that generally uses the word "so" to get to their point on any consistent basis.  It is something she does almost everytime now.  It's rather cute.