Emma suffers from obsessive-compulsive disorder and has romantic feelings for glee club director Will Schuester (Matthew Morrison), but she becomes engaged to football coach Ken Tanaka (Patrick Gallagher), as Will is married.

Ken ultimately breaks up with her on their wedding day because of her feelings for Will, and when Will leaves his wife, Terri (Jessalyn Gilsig), he and Emma share a kiss.

Their relationship is short-lived, and in the second season, Emma and her dentist boyfriend Carl Howell (John Stamos) marry in Las Vegas.

Mays feels the character has much depth, juxtaposing Emma's position helping the students with her own phobia of germs and love for a married man.

The character has been well received by critics, including Mike Hale of The New York Times, who praised Mays for being able to "[register] Emma's devastation with just the slightest widening of [her] enormous eyes.

She is dismayed to learn that Will's wife Terri (Jessalyn Gilsig) is pregnant and that he is considering leaving the teaching profession to become an accountant, but is able to convince him to reconsider by showing him a video of him singing.

[5] In an attempt to get over Will, Emma begins dating football coach Ken Tanaka (Patrick Gallagher),[6] and becomes engaged to him in the episode "Vitamin D".

Carl arranges a meeting with sex education teacher Holly Holliday (Gwyneth Paltrow), and reveals that they have yet to sleep together.

[19] They also agree to get married when Will returns, but the stress of planning a big wedding proves too much for Emma, and she leaves the church before the ceremony begins.

[20] She and Will eventually reconcile, and the two finally get married in the choir room with the glee club as witnesses in "All or Nothing", after New Directions win Regionals.

They are desperately trying to do so in the fifth season's tenth episode "Trio", and are caught having sex in the school by Becky Jackson (Lauren Potter).

During the final season, in the episode "Transitioning", she convinces a torn Will to choose what's best for him, to stay at Vocal Adrenaline with a promising salary and facility but unhappy or to stop.

In a parallel episode to the Pilot, 2009, she is aware and concerned with Kurt's depression and consults with his father about it and also convinces Will to stay with the Glee Club as the kids still needs him and that it what makes him happy.

In the series finale, "Dreams Come True", she is now living happily with the newly promoted Will as the principal and in the future they have more kids together.

In casting Glee, series creator Ryan Murphy sought actors who could identify with the rush of starring in theatrical roles.

Natalie Abrams of TV Guide noted that she had been waiting for them to kiss since the pilot episode,[31] and Eric Goldman of IGN has deemed their coming together "very hard to not feel good about".

[3] Dan Snierson, however, wrote that although there was satisfaction in the episode ending on the kiss, it may have been "more intriguing" to conclude when Will finds Emma's empty office, and having him then question whether it was too soon for the two of them to begin a relationship.

"[32] Emily VanDerWerff added: "I loved Emma's eruption to Will about how Sue Sylvester must have cheated and the kids deserved to win.

This stood as a contrast to the impulsiveness of Emma's new boyfriend, sexy dentist Carl played by the somehow always charming John Stamos.

"[24] Variety's Brian Lowry deemed the adult cast of early Glee "over-the-top buffoons", however opined that Emma offered "modest redemption".

"[2] Critics commented positively on the development of Will and Emma's relationship; TV Guide's Natalie Abrams wrote that she had been waiting for them to kiss since the pilot episode.

[38] Goldman wrote: "Schue and Emma finally coming together was very hard to not feel good about, even though you know it just won't be that easy when the show returns".

[39] In discussing Will and Emma's conversation about how she would have left Ken if Will had shown any interest in her, Pardue commented: "That's maybe the sweetest and the saddest thing I've ever heard."

"[41] Mays performed a cover version of "I Could Have Danced All Night" from My Fair Lady in the episode "Mash-Up", a studio recording of which was included as a bonus-track on copies of Glee: The Music, Volume 1 purchased from Target stores.

[42] Raymund Flandez of The Wall Street Journal called the performance "lovely",[43] and Andrea Reiher for Zap2it similarly praised the piece: "wow, she has a nice voice!

"[44] Eric Goldman for IGN commented: "Seeing Emma sing "I Could Have Danced All Night" was sweet, though was it just me (or my TV), or was the volume on her vocals a bit unusually loud?

[47] Erica Futterman of Rolling Stone remarked that having Emma in the role of Janet was "ideal", but preferred the song visually to vocally.

[48] Slant Magazine's Matt Zoller Seitz disliked the change in Emma's characterization which brought about the number, and while he wrote that "Mays was so charming that she almost, almost saved it", he ultimately found the "motivational contortions" insulting to the audience.

[52] In season three, Mays performs "Wedding Bell Blues" in the episode "Yes/No", which was described by Bobby Hankinson of The Houston Chronicle as "the perfect combination of a great song, plot relevance, and Princess Beatrice hat".

[54] TVLine's Michael Slezak described those vocals as "a breath of dewy spring air" and gave the song an "A", but Joseph Brannigan Lynch of Entertainment Weekly thought Emma was not "much of a singer" and gave the number a "B−", though he said "the curiosity of backup vocals from Coach Beiste and Sue Sylvester made this entirely worthwhile".