Further proof Princess Charlotte looks like Lady Kitty Spencer

Of the current generation of royal children, Princess Charlotte undoubtedly generates the most discussion and debate as to which royal relative she most resembles.

Some say she's a clone of her father Prince William, while others argue she's inherited her looks from her late grandmother, Princess Diana.

Many fans are also convinced she's the mini-me of Queen Elizabeth and even the Queen Mother.

There's photo evidence to support all of these claims, but perhaps the most surprising frontrunner for Charlotte's doppelganger is found on the Spencer side of the family tree.

Lady Kitty Spencer is the daughter of Princess Diana's younger brother Charles, the 9th Earl Spencer, making her a cousin of Prince William and Prince Harry.

With her blonde hair and blue eyes, the model doesn't look an awful lot like four-year-old Charlotte, her first cousin once removed, on first glance.

However, a new childhood photo shared on Lady Kitty's Instagram over the weekend says otherwise.

Perched on a horse, little Kitty has lighter hair than Charlotte, but very similar facial features.

The resemblance wasn't lost on her followers, with many remarking on how similar the two little girls look.

"Gosh you look like Princess Charlotte here," one wrote.

"Is that Charlotte? I can't believe my eyes," another said.

This isn't the first time parallels have been drawn between Charlotte and Lady Kitty, who is currently in Australia for the Melbourne Cup.

Last year, the model shared another photo from the family archives, this time on her first day of school, and Charlotte's resemblance was strikingly clear:

It's all in the eyes, the face shape and the hair, if you ask us — not to mention the cheeky attitude.

Evidently, the Spencer genes are strong in this little royal.

Take a look at photos of Prince William as a child and you'll see a striking resemblance in the father and daughter's facial features and expressions:

Then there's the similarity to Princess Diana, particularly evident in this photo released on Charlotte's first day of nursery school last year:

On the Windsor side of the family tree, Charlotte undoutedly takes after her great-grandmother Queen Elizabeth in plenty of ways.

Click through the gallery below to see their most lookalike photos: