Ivanka Trump appeared uncharacteristically angry as Texas Sen. Ted Cruz refused to endorse her father at the GOP convention Wednesday night
Credit: Jeff J Mitchell/Getty

Ivanka Trump is usually seen as the cool, calm and collected Trump, a quality that has been put to good use in her father’s presidential campaign.

But at the Republican convention on Wednesday night the daughter of Donald Trump appeared uncharacteristically angry as Texas Sen. Ted Cruz took the stage and refused to endorse her father.

Ivanka was photographed frowning and pointing her finger as Cruz, her father’s fiercest rival in the primary, told Republican voters at the convention to “vote your conscience, vote for candidates up and down the ticket who you trust to defend our freedom and to be faithful to the Constitution.”

In other words, the implication was, “don’t vote for Donald Trump.”

All of the Trumps – including Ivanka’s sister-in-law Lara, her half-sister, Tiffany, brother Donald Jr. and his wife, Vanessa – shared similar expressions of disdain as Trump supporters around them erupted into boos.

The GOP nominee himself then made his way into the audience to sit among his family. Both he and Ivanka appeared displeased as she leaned over to whisper something into her father’s ear.

Only when Cruz left the stage and her brother Eric began to speak did Ivanka’s smile resurface.

Related Video: Ted Cruz Taunted By Angry GOP Convention Delegates as He Refuses to Endorse Donald Trump

“She was very sullen until her brother started speaking and then she started smiling some more,” a source who attended the event tells PEOPLE.

The majority of the crowd appeared to share Ivanka’s feelings and began yelling, “Trump, Trump, Trump!” as Cruz spoke.

The billionaire businessman and son Donald Jr. later said that the Trump team knew in advance that Cruz wasn’t going to endorse Trump in his speech, with Donald tweeting that it was “no big deal.”

But the look on Ivanka’s face seemed to tell a different story.