Ivanka Trump's brand is booming, says the fashion firm, as one estimate says sales have jumped five-fold.
Abigail Klem, president of the US first daughter's eponymous clothing line, says it has seen "some of the best performing weeks" in its history.
The reported sales surge comes amid an ongoing boycott targeting business interests of the fashion entrepreneur's father, President Donald Trump.
Last month several retailers dropped Ms Trump's label, citing falling sales.
In an interview with fashion magazine Refinery29, Ms Klem declined to cite specific sales figures, but research by a market analytics firm seems to support the claim.
According to Lyst, a London-based e-commerce website which tracks clothing retail, sales of Ivanka Trump products rocketed in February.
It says sales increased 346% from January to February this year and 557%, compared with average orders last year.
"To see such an extreme spike in one month is completely unheard of and came as a huge surprise to us," says Lyst's US spokesperson Sarah Tanner.
Ms Klem said that most products are sold to women in New York, California and Texas, and the average shopper earns between $60,000-100,000 per year (£50,000-£82,000).
She said the political controversy surrounding President Trump, and the boycott, may have helped his daughter's brand.
The reported sales surge comes after Kellyanne Conway, a counsellor to President Trump, was accused of breaking ethics rules by promoting Ivanka Trump products during a live TV interview from the White House.
The first daughter's perfume is currently highest ranked on Amazon.com, with many shoppers leaving pro-Trump comments.
"I bought this without knowing what it smelt like, and I didn't care! I support the Trumps! MAGA! Who needs nordstroms!" Dustin M wrote, in reference to Nordstroms, which was the first retailer to drop Ivanka's products.
"Oh and by the way, the smell is aweosme!"
Another apparently happy customer wrote: "Bought this as a gift for my wife, and to support Ivanka's position."