Some parents chart their child's growth on a door frame or a wall at home, but for nearly 10 years, Lisa Christman unintentionally tracked her daughter's height on a Wicked poster outside a Pennsylvania theater.

Katie Christman was just 5 when she first heard the Wicked soundtrack and was immediately hooked, so when the show came to the Benedum Center in Pittsburgh later that year, her mom took her along.

"I've taken her each time since then," her mom told InsideEdition.com.

They saw it at the same theater again in 2008, 2011 and 2014, and each time, they'd stop for a photo. Unbeknownst to them at the time, it was in the exact same spot every year.

"It's funny because I didn't deliberately take the pictures that way," her mom said.

In 2011, Katie saw the show with a friend, and they went again together again this year. Her mom thought it would be cute to recreate the photo of the girls from 2011 so she snapped a picture of them together outside the theater.

When she returned home and looked at all the images, she realized her daughter had unknowingly been recreating the same picture since she was 5.

"I put them all together and it became a growth chart," her mom said.

The photos received tens of thousands of likes when they were shared on social media, including from Wicked 's own accounts.

"I didn’t know how much this show was actually a part of my life until I saw in the pictures," said Katie, now 14. "I was born in the year the show came out so watching me grow up literally with the show is pretty cool to see."

And she's still got more growing to do.

"Obviously we are going to keep coming back to Wicked every time it comes back to Pittsburgh," her mom said.

"And take the pictures!" Katie added.

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