Take a pic of the girls and then using a program like Photoshop, add text with how old they are and what their favorites are currently or what milestones they are at. A fun way to document them as they grow old!
Free Printable! Ask the same 20 questions year after year (1-18, but probably age 3 or 4 is a great age to start) and see how your child's responses change year to year. Makes a great keepsake to give to them when they turn 18.