Melania Trump has yet to speak out in the wake of President Donald Trump's mocking tweet directed at 16-year-old climate activist Greta Thunberg , in which he told the teenager to "work on her anger management" and "chill" out.

The President, a climate crisis denier, tweeted of her Time cover: "So ridiculous. Greta must work on her Anger Management problem, then go to a good old fashioned movie with a friend! Chill Greta, Chill!"

Just last Wednesday, Melania Trump tweeted a defense of her own child , whose name was referenced in a pun by an impeachment inquiry witness.

"A minor child deserves privacy and should be kept out of politics. Pamela Karlan, you should be ashamed of your very angry and obviously biased public pandering, and using a child to do it," Melania Trump tweeted after Karlan, a law professor, mentioned Barron Trump during impeachment hearings on Capitol Hill. Karlan later apologized for making reference to the youngest Trump child's name.

Stephanie Grisham, who serves as top communication aide for both the first lady and the President, defended the first lady's silence in a statement on Friday.

"BeBest is the First Lady's initiative, and she will continue to use it to do all she can to help children. It is no secret that the President and First Lady often communicate differently -- as most married couples do. Their son is not an activist who travels the globe giving speeches. He is a 13-year-old who wants and deserves privacy," Grisham said.

But one of the President's advisers told CNN it is "100% hypocritical" that the President tweeted about Thunberg in light of the controversy involving the invocation of Barron Trump's name last week on Capitol Hill.

The first lady's "Be Best" initiative for helping kids includes a portion dedicated to specifically promoting kindness online and preventing cyberbullying against children. In a speech in May 2019, Melania Trump marked the one-year anniversary of the program's launch, saying: "I ask you again to join me in my commitment to promoting values such as encouragement, kindness, compassion, healthy living, online safety, and respect in our children."

The juxtaposition has lead to criticism in the wake of the President's most recent broadside on Thunberg (who appeared to take it in stride by paraphrasing his tweet and making it her Twitter bio).

It's not even the first time the President has mocked the teenager on Twitter. In September, after Thunberg made an emotional United Nations speech calling the failure of leaders to act on climate change "a betrayal," he sarcastically tweeted that she "seems like a very happy young girl looking forward to a bright and wonderful future. So nice to see!"

And while Melania Trump hasn't addressed the hypocrisy directly this week, it's something that's come up previously regarding her husband's Twitter.

"It is not news or surprising to me that critics and the media have chosen to ridicule me for speaking out on the this issue, and that's OK," the first lady said last year in opening remarks at the Family Online Safety Institute's conference in Washington. "I remain committed to this topic because it will provide a better world for our children, and I hope that like I do, you will consider using their negative words as motivation to do all you can to bring awareness and understanding about responsible online behavior."

For the past 24 hours, Twitter has been filled with memes and statements mocking the first lady's Be Best platform in light of the bullying of a child demonstrated by the President, and the first lady's ongoing silence on the matter.