Kate Middleton is one proud mom of three beautiful growing kids who are into many hobbies and activities. She recently shared in a royal event that her youngest child with Prince William, Prince Louis, who is now almost two years old, has a classic favorite song.

During the Place2Be 25th Anniversary event in Buckingham Palace, the Duchess of Cambridge was reportedly chatting with members of a performing school choir. She learned that a couple of them were celebrating their birthdays and she revealed that the Birthday Song is Prince Louis' favorite.

Kate also joked that she should be singing "Happy Birthday" to the celebrators. She also said that it's too bad her youngest son won't be able to hear the choir as he's all set for his bedtime at their home in Kensington Palace.

Prince Louis is apparently a music lover who likes to dance and sing. Kate honed this on him as the child is exposed to a musical toddler playgroup. The Duchess of Cambridge personally brings her son to this social and educational activity.

According to reports, the musical toddler classes cost $15 per session. Called Monkey Music, the activities are actually designed for parents and kids to work and play together.

But it's not just Prince Louis who is into music. Older brother Prince George is getting ballet lessons and has recently been learning to play the guitar.

Meanwhile, Kate surprised some passers-by in the streets of London when she was seen going around to check out shops one weekend. The Duchess of Cambridge was spotted going to Waterstones to buy some military-themed books for kids. It's speculated that the books are for Prince George and Princess Charlotte.

During her very casual outing, Kate wore a light blue sweater, jeans and black loafers. She acted like she was on a weekend errand after a long work week. The Duchess of Cambridge actually just returned from her royal trip to Ireland when she was seen shopping for books.

Later that week, Kate was with Prince William for the Commonwealth Day service. The Duke and Duchess of Cambridge were reunited with Prince Harry and Meghan. However, many royal fans were disappointed that the former Fab Four didn't have more interaction at the royal engagement since it was a solemn affair.

Prince William and Kate will press on with their various duties this week despite the global health crisis brought by the coronavirus. The Duke and Duchess of Cambridge are also set to fly to Australia in the coming months to visit those affected by the bushfire.