Riri Williams proved to be a worthy successor to Iron Man, before forging her own path as the hero Ironheart. The character has grown to be immensely popular and has gone on to be a key member of the Champions while assisting the Avengers on occasion. Williams is one of the smartest people in the Marvel universe and is even smarter than her former mentor, Tony Stark.
Williams made her first appearance in the Invincible Iron Man (2016) and was created by Brian Michael Bendis and Mike Deodato. At 15, Riri attended M.I.T. on a scholarship and designed her own version of Iron Man armor using stolen materials. After Tony sees her potential, he becomes her mentor. She adopts the codename Ironheart and becomes her own hero - eventually joining the Champions. Make no mistake, Riri is more than Stark's protege - in fact, she's superior intellectually, at least according to Bendis.
If being an M.I.T. student at age 15, creating her own suit of Iron Man-inspired armor, and becoming a superhero without superpowers doesn't convince you Williams is a genius, Bendis admitted in an interview with Time Magazine from when the character made her debut that she's smarter than Stark:
She’s smarter than Tony...As we say in the story: high intellects, out of frustration, can sometimes retreat into their own world. This young woman has had that burden but she also has a grounded parent who helped her get to this point. But she also has had terrible tragedy that has informed her more than anything.
It's not an exaggeration to suggest Riri is smarter than Tony. Not to take away anything from Stark and his accomplishments, but what separates the two is a life experience. Both were on similar paths at the same age (Tony even got into M.I.T. at 15 as well). However, Stark was born into wealth and privilege, where Williams had more of a grounded upbringing. She didn't have the same access to money and opportunity and used her intellect to succeed despite it. Again, Stark is one of the smartest people in Marvel Comics and his inventiveness and intellect are incredible - few rival his genius. But, as Bendis suggested, Williams is smarter.
Tony helped Riri on her path to becoming a full-fledged hero, but Williams created the opportunity for herself and ran with it. She's a self-made hero who just so happened to be one of the smartest people on Earth - just like Tony before her. It's what makes Ironheart such a beloved hero.
Source: Time Magazine