In the universe of "The Smurfs" there were only two female smurfs. There was "Sassette" who was one of the child smurf characters added towards the end of the US run of the cartoon, and then there was Smurfette, who had existed as a character since almost the very beginning. She was around long before the cartoon even existed*.
Smurfette was more feminine looking than the average smurf, with long blond hair and girly eyelashes. She always wore a white dress and white high heels. No one ever explained how she managed to walk around the forest in high heels, but she did.
Smurfette was not a real smurf. She was a golem, a construct, a robot, an artifical being. She was created by the warlock Gargamel for the express purpose of creating discord in the smurf village. Gargamel postulated that introducing a female into the all male smurf environment would awake a spirit of competition, and cause jealousy amongst the smurfs. He was right.
She originally looked a whole lot like a male smurf in drag. She had dark spiky hair and wore a dress. The other smurfs made fun of her. She would attempt to be girlish, but she was ugly and everyone thought of her as a nuisance. But Papa Smurf felt sorry for this pitiful creature, so he took her in and used his special Smurfery skills to turn her into the Smurfette that we are all familiar with.
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The new attractive Smurfette actually caused the problems that Gargamel had hoped for in the beginning. The entire smurf village fell in love with her. They fought each other over her, and everything turned into a big mess. She caused quite a bit of trouble, and eventually decided she wanted to go back to Gargamel.
The other smurfs were totally shocked when they heard her say that. So they put her on trial. Jokey Smurf acted as her lawyer. She was declared "not guilty" by a group of smurfs who were all in love with her.
After the trial she ran away from the village. She would reappear from time to time and eventually moved back into the village. She remained the love interest of all the smurfs, but they had learned their lessons, and there would be no more dangerous competition over her.
*The Smurfs were around for well over twenty years prior to the cartoons, there were toys, books, comic books, and a few animations dating back to the late 1950s.