Beginning this past May on Harper's first birthday, we started marking her height and recording it on an armoire we have (that is technically Hayden's but they are both utilizing it for our "growth chart tradition").
For the time being, we will do this every 6 months - eventually we will do it annually.
Here are the marks:
And here she is this past May having her 1-year-old mark made -
And here she is just yesterday having her 18-months-old marks made -
she is holding one of my baby doll's I had as a child