The once-in-a-lifetime celebration honors the queen’s historic 70 years on the British throne.

Prince Harry and his entire family will also be attending, a spokesperson announced (viaCNN).

One royal expert, however, says otherwise.

Queen Elizabeth at a royal event in 2011

Will Archie and Lilibet be a delight or a burden for the Queen?

Queen Elizabeth is a doting great-grandmother in addition to being a monarch.

But royal biographer Angela Levin thinks the Sussexes should have picked a better time for a family reunion.

Meghan Markle, Prince Harry and Queen Elizabeth 2018

“The Queen is going to be very heavily in demand.”

Levin added that Harry and Meghan should have been more considerate.

Like other anti-Harry pundits, Levin thinks their Jubilee trip is just an attention-getting ploy.

“But with so much going on during the Jubilee, it is just the wrong time.”