US Open women's semifinals: Aryna Sabalenka faces Emma Navarro and Jessica Pegula plays against Karolina Muchova

Despite an easy fourth-round win over Diana Shnaider, there was something that bothered Jessica Pegula.

“The most annoying thing is that people think I have a butler,” the 30-year-old American said on Monday.

“That I get chauffeured around. That I have a private limousine. That I fly everywhere in a private jet.”

“I’m definitely not like that.”

The misconceptions about her lifestyle stem from her family's wealth. According to Forbes magazine, her father Terry, an oil and gas magnate, has a fortune of $7.7 billion (£5.9 billion), making him the 371st richest person in the world.

She is not the only billionaire's daughter in the semifinals of the US Open on Thursday.

On the other side of the winning line is Emma Navarro. Her father Ben owns a credit card empire worth $1.5 billion (£1.1 billion), according to Forbes.

These are figures that dwarf even the $3.6 million (£2.7 million) prize money for the Flushing Meadows winner – the highest prize money in tennis.

But there is still a long way to go before Pegula and Navarro can sign up for a blockbuster and lucrative, all-American title fight.

Two-time Australian Open champion Aryna Sabalenka, the highest seed remaining in the field, showed strong form heading into her meeting with Navarro, while underdog Karolina Muchova has a happy habit of scoring big wins as she prepares to face Pegula.

BBC Sport looks at the form and stories of the four semi-finalists.