Trump is scheduled to leave for his presidential retreat in Maryland, while Melania will remain at the White House over the weekend. The tweet also doesn't count as a public appearance, which means at the time of writing, it's now been 23 days since she was verifiably spotted.
The first lady was last seen May 10 when she and Trump welcomed home three Americans who had been released from detention in North Korea.
Just four days later, Melania was hospitalized for "an embolisation procedure to treat a benign kidney condition" at Walter Reed National Military Medical Centre.
Mrs Trump's lack of appearance at events she would normally be expected to attend has created headlines in the U.S. media and triggered conspiracy theories.
But, Huffington Post compared Melania's tweet with previous tweets from the President, and they pointed out that "working overtime" is one of the President's favorite phrases.
In a tweet storm on Friday, Black wrote: "I've been obsessing a bit over Melania's disappearance - and that's what it is".
President Trump told Reuters Thursday that his wife is "in great shape" after her surgical procedure.
Despite Trump's assurances, reporters saw no sign of the first lady watching from above.
So, where could the first lady be?
As frenzied speculation began about Melania's quality of health and what she could possibly be doing, she took to Twitter on Wednesday to quell any untoward rumours.
According to CNN, Grisham again stated on Friday that Melania "is fine, she's doing great".
He responded to a question about FLOTUS' whereabouts by pointing to a White House window and saying: "She's doing great".