Since joining the Royal Family, Kate Middleton has become both a family and fan favourite after marrying Prince William.
The Duchess of Cambridge has developed a very good relationship with his grandmother, the Queen, who, despite their age gap, seemingly have a lot in common.
The two women clearly have a deep respect for one another, and Kate showed this in a silent but powerful manner at Prince Philip's memorial service last week.
As reported in The Mirror, eagle-eyed royal fans noticed that as the Queen entered Westminster Abbey, Kate straightaway curtseyed.
Footage from the service shows Kate bobbing down to perform the gesture as Her Majesty passed by when walking to her seat.
Shortly afterwards, as the Queen passed by Sophie, the Countess of Wessex, and her daughter Lady Louise Windsor, they too curtsied towards her.
However, not all royal women were seen performing the gesture for the Queen as she entered the Abbey for the memorial service.
And the rules surrounding who should curtsy and when may explain this.
They are only performed to the monarch on their "first meeting of the day" - this means it's likely that Kate, Sophie and Louise hadn't seen the Queen that day before they curtsied.
Therefore it is also likely that the other royal women didn't curtsy as they had already seen the Queen earlier that day.
As well as attending the service with husband William, Kate also brought her two oldest children Prince George and Princess Charlotte.
The youngsters walked into Westminster Abbey with their parents before taking their seats in the row behind the Queen and Prince Charles.
The eight-year-old future king and his six-year-old sister looked slightly nervous when they got out of the car and walked towards the building, however some reassuring words from mum Kate saw Charlotte start smiling.
According to lip reader Jacqui Press, Kate whispered to a very serious and nervous-looking Charlotte, "you can smile", reports MailOnline.
The princess, who was holding her mum's hand, then broke into a big grin.
Meanwhile, William held George's hand and gave him some instructions, saying: "Let's go in".
He then guided his son toward the dignitaries and introduced them.
George – who is likely to one day become monarch – and Charlotte’s appearance marked a key moment in their public lives, being the first major televised church service they have attended.
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