Fuller House failed to feature Michelle because the Olsen Twins refused to return, but the show could've simply recast the role with any of these actresses. Netflix's spin-off sequel to the late '80s/early '90s sitcom debuted in 2016. It lasted for five seasons, wrapping up in 2020. However, throughout its run, Danny Tanner's (Bob Saget) youngest daughter never appeared on the screen.
Every single prominent cast member from Full House returned for the offshoot except for the Olsens. Before Fuller House premiered, there were contradicting reports regarding the sisters' involvement. After the first season, many continued to hold out hope that they would still appear, but that never happened. While the show initially made an effort to include Michelle in its storytelling via various references, the character was ultimately cast aside leading up to the end, and worse, she was only ever brought up to make fun of. Even when both of her sisters, DJ (Candace Cameron-Bure) and Stephanie (Jodie Sweeting), tied the knot at the same time, there was no mention about their youngest sister and why she wasn't attending the wedding.
While she is only one character, Michelle's absence was felt throughout Fuller House's run. She was one of the best parts of Full House, so understandably, long-time fans of the franchise were looking for her. Granted that the offshoot did offer an explanation about why she was no longer in San Francisco, it seemed odd that she never once came home in half a decade. More than that, the fact that she wasn't around during some of the most important moments in her sisters' lives was contradictory to Full House's core theme of family. Creator Jeff Franklin revealed that they never truly considered recasting the role, even when it became clear that Mary-Kate and Ashley weren't returning. However, with the Olsen Twins' unchanging stance on the matter, it shouldn't have been a big deal if they hired another actress to play the part. Especially so when there are several other actresses that could have done the job well.
Elizabeth Olsen
As the sister of Mary-Kate and Ashley Olsen, hiring Elizabeth Olsen as Michelle in Fuller House would've been Netflix's best option. The actress is good at everything she does, and her recent performance in WandaVision proved that she'd be equally good in a sitcom setting. There was actually some confusing information about Fuller House supposedly seeking Elizabeth for the gig. The producers claim that they reached out to her and were turned down, but according to the Marvel star, she was never contacted. Granted that actually offering her the part isn't a guarantee that she would've gone for it, especially since she's also busy with other projects, it's not outside the realm of possibility that she would've gone for the gig. After all, she said it herself; she grew up visiting the set of Full House, so while she was never in the show, she had some personal connections to it. Whatever the case may be, not booking her for the spin-off was a big missed opportunity.
Kaley Cuoco
Having starred in one of the most popular sitcoms of all time in The Big Bang Theory, Kaley Cuoco would've also been a great candidate to play Michelle in Fuller House. That said, considering the fact that she was also busy playing Penny in the CBS series during the Netflix sequel's run, being a guest star would have certainly sufficed. This would actually make a lot of sense since the youngest Tanner daughter is based out of New York. Cuoco has similar physical features to the Olsen Twins, as well, considering all of them are blonde, petite ladies; she could've easily waltzed in the set of Fuller House in her Penny costume and easily have passed as Michelle. One bonus point is that Cuoco has a great rapport with John Stamos; the pair recently filmed a bit for W Magazine, where they sang the Full House and The Big Bang Theory's theme song, respectively, and they seemed to have a good time. For what it's worth, Stamos could've possibly asked Cuoco himself if she would do the gig since they're also apparently neighbors.
Olesya Rulin
If Netflix wanted to feature Michelle more regularly to make her a mainstay like she was in Full House, the producers could've tapped Olesya Rulin to play the part. Best known as Kelsie in the original High School Musical movies, the actress not only bears a striking resemblance to the Olsen Twins, she's also the same age as them. Looking at her recent film and TV appearances, Rulin would've been best positioned to be recast as Michelle in Fuller House as a series mainstay. The fact that she wasn't associated with any other projects other than the Disney movie would've made it easier for people to get acclimated to her portraying the beloved Full House character. For what it's worth, there was even an online petition pushing for this.
Hilary Duff
A few years younger than the Olsens, but Hilary Duff could've also been tapped to play Michelle in Fuller House. Like the aforementioned actresses, she could easily pass as the grown-up version of Mary-Kate and Ashley Olsen's Full House character, with her blonde hair being a signature trait. As a former Disney star, headlining her own show, Lizzie McGuire. Duff evokes nostalgia, exactly what the spin-off aimed to do. She also fits in the family-centered and kid-friendly brand of the sitcom. While some might find it difficult to see her as Michelle and not Lizzy, Fuller House might have also benefitted from the actress' wide fan base, with Duff's loyal followers checking in the Netflix show just to see her. Finally, the fact that she's musically inclined could've meant more bonding between Michelle and Stephanie, who became a world-renowned DJ and singer. Perhaps, they could have even roped in Uncle Jesse (John Stamos) and his old band for a fun jamming session.