Kate Middleton was spotted spending quality time with her son, Prince George.

According to a report in People, the 32-year-old Duchess of Cambridge, who was at Holland Park, was pretending to be a monster and chased her 22-month-old son.

"It looked like she was pretending to be a monster, flailing her arms about and chasing him," a source said.

"She was play-acting just like all mums do and he was running around loving it – he looked very happy," the insider added. "They had matching waxed-green coats on, similar to a Regatta [brand], and dark jeans with boots. They both looked matching!"

"He looked like such a happy lad, being chased by his mom and enjoying the swings, slides, roundabouts – they were going on everything. They looked just like any other mom and toddler," the source revealed.

Kate Middleton and Prince William welcomed their second child, Princess Charlotte, on 2 May, weighing 8lb 3oz, just two hours after Kate was admitted at the Lindo Wing of St Mary's Hospital.

The onlooker revealed that Kate Middleton showed no sign of newborn exhaustion.

"They both looked really well," the insider said.

It was previously reported that Kate Middleton will make her first public appearance since welcoming Princess Charlotte on 13 June.