Shy Princess Charlotte adorably hides behind mom Kate Middleton on the first day of school

Princess Charlotte may be known for her sassy faces and adorable waves, but all bets are off on her first day of school!

The royal, 4, arrived at Thomas's Battersea in South London on Thursday morning alongside big brother Prince George and parents Kate Middleton and Prince William. However, according to videos shared by the royal family, the normally outgoing princess definitely felt a little nervous on her big day.

While walking in to meet the head of the lower school Helen Haslem, Charlotte instead hid from Haslem and photographers behind mom Kate. It was only after a nudge from Duchess Kate and seeing Prince George, 6, greet Haslem that Charlotte did, too!

According to People, the Duke and Duchess of Cambridge then accompanied their daughter to her classroom, where she'll join 20 other students for a semester of computing, French, art, drama and ballet, in addition to math and reading.

The $23,000-a-year private school chosen for the two eldest Cambridge children was seen as an unusual choice by Will and Kate, who chose to forgo the elite and traditional "Eton-style" feeder many royal members have attended in the past. Located in an "aspirational area" of the city, the prep school introduces its students to a spectrum of classes, including art, dance and foreign languages.

According to its website, it also emphasizes social responsibility, kindness, courtesy and confidence as some of its core values.

For more on Charlotte's big day, watch the video above.