Fans furious over Harry and Meghan's birthday message to Charlotte

Princess Charlotte turned four yesterday and the palace released new photos of the young royal, much to the delight of fans the world over.

There was an outpouring of birthday messages and love for the pint-sized royal on social media, but one couple’s attempt at wishing her well didn’t go the way they thought it would.

Kate Middleton and Prince William shared three new images of Princess Charlotte to their Instagram page to mark the milestone, and fans were ecstatic, until a few eagle-eyed observers spotted a comment they thought was inappropriate.

Though the images have each been liked over one million times, it’s the comment left by Harry and Meghan which has got everyone talking.

“Happy Birthday Charlotte!” the comment read. “Lots of love, H and M xo”

The message was accompanied by a cute pair of cake and balloon emojis, but the wording drew the ire of Kate and Will’s followers for a very small reason - they didn’t call her Princess.

The comment attracted almost 2,000 replies many of which were scathing of the pair’s attempt.

“Even on Kensington Royal (her parents' Instagram account) she is referred to as Princess Charlotte. Meghan is just being disrespectful like she was to Prince Louis," one wrote.

"So why they call her princess? Because it's a sign of respect!! Even Queen's account calls her princess," another concurred.

“I think that’s “Princess Charlotte” to you,” another wrote.

Other’s sprang to their defence.

“It is not disrespectful.. she is her niece,” one pointed out.

I actually love this!!” gushed another.

Another pointed out that typically the family to no address each other by their titles.

"Just last week William was talking about CHARLOTTE without referencing her title,” the astute observer wrote.

“Will and Harry always refer to each other as 'my brother Harry' or 'my brother Will' they NEVER use titles.”

It’s a familiar debate to royal watchers, the same issue was taken with the pair’s birthday message to Prince Louis last week.

The couple are expecting their first child any day now, and with an ambulance spotted in their neighbourhood it looks like they might have enough on their plates without responding to an Instagram controversy.

A Palace source told CBS News yesterday morning that the baby 'hasn't been born yet'.

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