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 (Â£50,000-Â£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."

Set 240 to win, Michael Klinger (53) and George Hankins (67) added 99 for Gloucestershire's second wicket.
Taylor then smashed 64 from just 36 balls before being out with the scores level, but the visitors sealed victory.
Luke Wright had earlier made 84 for Sussex, but was caught behind off the impressive Chris Liddle (5-52).
After Wright fell on 182-5, having earlier been aided by Laurie Evans' 48, Sussex's batsmen struggled, with only Jofra Archer (30) making any real impact on the scoreboard.
Both sides are now on three wins after seven matches, but Sussex have a point extra after their rain-ruined match against Middlesex.
They can still make the top three - and a place in one of the two quarter-finals if they beat Hampshire at Southampton on Wednesday and Surrey lose to Gloucestershire at Bristol.
Gloucestershire's Jack Taylor:
"I'm hitting the ball well at the moment and it was nice to get us over the line for a good victory. We've just been too inconsistent in this format but we played well today.
"We weren't sure what a good score was going to be but we bowled well, especially Chris Liddle, and then Michael Klinger and George Haskins set things up nicely for me and Ian Cockbain at the end.
"Although we can't reach the knockout stages it's important to keep playing good cricket, not least because a lot of the skills are used in T20. It's good practice for that."
Sussex head coach Mark Davis:
"It's incredibly frustrating because we have played a lot better in this format but we have twice got ourselves in good positions and not won either game.
"We thought we had a competitive score but we got ourselves into a good position and then kept losing wickets at crucial times. They then set the game up with the way Klinger and Haskins batted.
"If we win the last game we'll give ourselves a chance of making the knockout stages so there is still a lot to play for."
Ivanka Trump's brand is booming, says the fashion firm, as one estimate says sales have jumped five-fold.
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Jack Taylor's fourth One-Day Cup half-century of the season helped Gloucestershire to a six-wicket win over Sussex with eight balls to spare.