They did not, at least on the YouTube official RNC channel, except that he showed several photos of his dad.
Early in the campaign, he casually mentioned that his sister Mary Anne, who is a Federal judge, would make a great SCOTUS justice, which set off a firestorm because of a past decision of hers in support of abortion. So possibly he has shied away since then. But Melania's speech also mentioned every one of his parents and siblings as well as her parents and sister, and or course the children. I was glad to hear that. The only names she didn't mention were Ivana and Marla -- LOL! But I saw Marla photographed with Tiffany the night of Tiffany's speech, and it's probable that Ivana was there to see her wonderful kids, too. Maybe they had a skybox for a few VIPs and influential private persons.
I’ll bet anything that Ivanka was watching the convention.
It would be a proud moment for any parent watching all three of her children featured in their speaking roles. They have so far made good impressions with the public.
Baron is too young, and it would be too much pressure to put on him just yet.