Smurfette Breakout

It's often that many shows feature a bigger ratio of males to females in their characters, with The Smurfette Principle being pretty widespread. However a lot of the time this can work in favor of the female character. Being the only female in a largely male environment makes her stand out and be distinctive from the rest of the show's male characters. If the writers have written her well and avoided most Positive Discrimination, then chances are she will become popular with the viewers. If her popularity rises high enough, she might even become a Breakout Character.

The area in which this is most common is Professional Wrestling. It's a rather frequent occurance for a woman to be introduced as someone's manager or valet, usually for a tag team, and end up becoming more popular than the wrestler they're managing. Often if the team splits, the woman will fare much better because she can be integrated into the women's division while the men will often become lost in the shuffle.

Note that this is not simply about a female becoming a Breakout Character. There must be a majority of males compared to females for this to count. The character need not be the only woman on the show either. See also Ensemble Darkhorse and Breakup Breakout.

Examples of Smurfette Breakout include:

Film

Out of the three leading actors in the Harry Potter movies, Emma Watson has received the most publicity. While Daniel Radcliffe and Rupert Grint have gotten a large amount of roles, it is Emma who has remained in the public eye the most.

Music

Gwen Stefani of No Doubt, though she was The Face of the Band to begin with. The video for "Don't Speak" shows her taking the spotlight and starring in all the publicity photos, while her three (male) bandmates languish in obscurity.

Puppet Shows

In The Muppet Show, Miss Piggy, one of the few female Muppets, was initially only a minor character but her popularity skyrocketed and she is now probably the most famous of them, along with Kermit.

Professional Wrestling

Out of the recent season of Tough Enough which featured five female contestants against 11 males, three of the women who were on the show have now been signed by WWE. The (male) winner hasn't even debuted in FCW yet.
- The first woman eliminated became the first one to debut on WWE TV regularly (as one of Brodus Clay's dancers) while winner Andy got released after a few months in developmental.
Older Than They Think: The Fabulous Moolah was initially a valet for Buddy Rogers but eventually branched out on her own and became a pioneer for women's wrestling. She is recognised as the first ever WWE Women's Champion and held it for over twenty years.
Sable was first Triple H's valet and then Marc Mero's. The fans cared more about Sable than Mero, and she was given more attention and storylines and is now recognised as the first true WWE Diva. This also happened to Mero's second valet, Jacqueline, though she didn't become quite as big a star as Sable.
Sunny first debuted as the valet for the Bodydonnas. She became much more popular than they did, and was booked as the manager of several different wrestlers (The Godwinns, Farooq Asad, even the Road Warriors briefly). However she was a few years early for the Attitude Era and so wasn't able to reach the popularity level that Sable did.
Remember T&A? Test and Albert? A few people probably do remember them and some probably will remember that they were in a tag team but who was their valet again? Oh yeah...Trish Stratus.
Trish's arch-rival, Lita, benefited from this as well. She debuted as a valet to Essa Rios who was meant to be a pioneer of the Light-Heavyweight division. He ended up lapsing into obscurity while Lita became popular with the fans for her high flying moves. She averted this when Team Xtreme broke up, as all three of that group have remained well known.
Anyone remember the team of KC James and Idol Stevens known as the Teacher's Pets? Probably not, but they do remember Michelle McCool, who was their valet and went onto become the first Divas' Champion as well as one of the prominent figures of the women's division - not to mention Mrs. Undertaker.
- As of 2012, KC James has been released from WWE and is toiling away on the indy circuit. Stevens was sent back to developmental where he was repackaged as Damien Sandow, tore up FCW, and soon earned the attention of WWE's higher-ups as a possible future star. He has since reappeared on WWE main programming, so time will tell.
Happened with MNM, arguably. Joey Mercury got released twice and faded away and John Morrison is permanently stuck in midcard purgatory while Melina broke out on her own and became Women's Champion and was surprisingly popular after her Heel Face Turn.
Happened again when the Hart Dynasty split. David Hart Smith got released, Tyson Kidd is now mostly competing on NXT, but Natalya got put back into the women's division and pushed to win the title.
Chyna benefitted from this both in and out of the ring as well. She became extremely popular with female fans for competing in the men's division and got a lot of mainstream exposure.

Video Games

Yuna and Rikku were two of only three girls in a party of seven characters in Final Fantasy X. Yuna was the main character's love interest while Rikku was a supporting character. The direct sequel revolves around them and new character Paine. Word of God has said that there were originally meant to be two spin off games with one focusing on Yuna and the other on Rikku but they eventually got combined into the one game.
- Not entirely a great example, the rest of the cast was either even less significant than Yuna and Rikku in terms of plot or dead and/or no longer existed.
Nina Williams, the only woman to have appeared in every Tekken game, got her own spin-off game titled Death By Degrees based off her assassin background.

Western Animation

Jasmine from Aladdin is a supporting character while the story is about Aladdin, but she is included in the Disney Princess franchise and is actually the only princess in the lineup who isn't the main character in her film.
Tinkerbell from Peter Pan got her own spinoff franchise in the Disney fairies.
She Ra Princess of Power was actually introduced with this in mind.
Penelope Pitstop was the only female racer on Wacky Races and got her own spinoff series.
Avengers Earths Mightiest Heroes: The Wasp was the only female Avenger during the first season, and went on to become the show's most popular character by far.

Other

The Tudor family in English history had five rulers, three men and two women. Elizabeth I is undoubtedly the most famous and iconic of the five, having had the most stories and films made about her. Also, the next best known, Henry VIII, is only really remembered for marrying six different women.
- Henry the VIII also led the English Reformation, the single most important event to occur during the Tudor dynasty, though that was linked to the six women. He was never well liked, which was he was less popular.