Kate Middleton has been dropping out of her royal functions purportedly due to post-partum blues and marriage troubles.

But Daily Mail reported that Queen Elizabeth herself convinced Kate Middleton to come out of her self-imposed hiatus to attend an official function on Sept. 9 when she becomes the longest-reigning monarch.

"The Duke and Duchess of Cambridge will be with the Queen at Balmoral on September 9. They will attend a family dinner that Her Majesty will give that evening," the article said.

It added, "Kate's invitation follows a deep tribute that William paid to the Queen in the foreword to a biography of Her Majesty by former Foreign Secretary Douglas Hurd, which is being published to coincide with the historic date."

After giving birth to Princess Charlotte, Kate Middleton just couldn't catch a break from the tabloids as she was reported to be struggling with post-partum depression and her crumbling marriage to Prince William.

According to Celebrity Dirty Laundry, Prince William and Kate Middleton seem to be following the footsteps of his parents, Prince Charles and Lady Diana.

Apparently, Prince Williams was really in love with Isabella Calthorpe, instead of Kate Middleton, reminiscent of Prince Charles being really in love with Camilla Parker-Bowles instead of Lady Di. This is also allegedly the reason why the Duke of Cambridge was banned by his wife from attending Calthorpe's wedding to Sam Branson.

"Kate and William have seen firsthand how their split would be handled," it said. "During their month long separation in September 2014, Kate Middleton took refuge at her parents' home in Bucklebury, while Prince William continued to royal duties."

The couple wouldn't have reunited if not for the intervention of Queen Elizabeth who allegedly admonished the couple to attend to their royal duties.

The Palace has yet to respond to all the rumors regarding Kate Middleton's post-partum depression and also the alleged marriage troubles with Prince Williams.