I guess she didn't see the sign

First lady Melania Trump was greeted by demonstrators holding [signs] referencing her husband's past remarks upon landing in Malawi on Thursday morning.

The Associated Press reported that among the demonstrators, who were white, one woman held a sign reading “#MELANIATOO,” with the “ME” written in black, bold letters. Another couple held up a sign that read, "Welcome to Malawi. #NOTASHITHOLE!" according to the outlet, a reference to President Trump's remarks earlier this year in which he reportedly referred to immigrants from Haiti and African countries as coming from “shithole countries.”

  The Hill

I was going to say something rude about wishing in one hand, but I'll offer some kind advice instead: Then don't be a dick about what you wear on your FLOTUS publicity tours.

...but hey, do what you want...you will anyway.

UPDATE:

Here's another look she chose.

Her decision to appear at Nairobi National Park wearing a white pith helmet, crisp white shirt and light brown jodhpurs made headlines in international media, which correctly described the pith helmet as a symbol of colonial rule.

So much about the concrete history of white supremacy is poorly remembered or conveniently forgotten. As such, it may be difficult for many to understand why the US first lady chose to dress up in the costume of a colonial settler in Kenya in 2018.

[...]

Nineteenth-century colonists were supported by leading scientific and medical opinion in their belief that solar radiation in "the tropics" attacked white people's nervous systems and rendered them infertile. Other symptoms of exposure were thought to include laziness, depression, outbursts of excessive passion, insomnia and memory loss.

[...]

Pith helmets were often worn by colonisers alongside other protective paraphernalia, such as red vests and "spine pads" (a quilted piece of cloth) worn down the back of the shirt to protect the nervous system from the feared "actinic ray".

[...]

Conveniently for wealthy whites in the colonies, other medical recommendations included forbidding whites from doing manual labour outdoors (they were to undertake supervisory roles only), vacationing to cooler climates at regular intervals, and the repatriation of white children from the colonies after the age of five (typically to an expensive private boarding school back "home").

[...]

The pith helmet is sometimes used to denote a "frontier" spirit of adventure and intrepid exploration.

  al Jazeera

I'll give her the benefit of the doubt on that count, since neither she nor her husband appear to have any interest in or knowledge of history.

This is wrong. In fact, their historical social role was to emblematise white fragility and anxieties, as well as blurring the distinction between white civilians and the colonial police and military, who also wore pith helmets.

Colonialism extracted labour and resources from "natives" by ordering colonial societies through extreme and everyday forms of violence. But it was always necessary to insist that despite enjoying the protection of colonial states armed to the teeth in order to immiserate and exploit subject peoples, it was whites - and white women, in particular - who were the most vulnerable group in the colony.

In this sense, the pith helmet represents not only colonialism, but whiteness, too. We might think of whiteness as an identity that always noisily insists on its own vulnerability (despite social and economic realities to the contrary) as the principal justification for the oppression of racialised others.

[...]

My own view is that the US first lady's decision to wear a pith helmet was appropriate and should be taken seriously. The regime she represented in Kenya is a white supremacist one. Her husband campaigned successfully under the fascist slogan "America First," and has since implemented his "Muslim ban" and encouraged the detention of migrants, including separating children from their parents and keeping them in "tender age" cages.

The policies and ideological grounding of the current US administration - and the bogus fears animating its supporters - represent a continuation of earlier forms of imperialism. There is no attempt to disguise the fear and hatred towards people of colour, at home or abroad. The pith helmet makes the connection quite clear.