they broke up
Minerva challenged Arachne. Arachne won; Minerva was jealous so she turned her into a spider.
In the Roman myths, Minerva turns Arachne into a spider.
For declaring her weaving to be better than Minerva's
Spider
Do you mean Arachne? If so, she was a weaver of spectacular skill whose vanity cost her life. She boasted publicly that she was more skilled at the loom than even Minerva, who was the patron of the art. Upset by this, Minerva made her presence known and challenged the girl to a contest. And while Arachne's weaving was sublime, Athena's was divine and all declared her easily the winner. Arachne, in shame, tried to commit suicide by hanging herself, but Minerva would not have it, instead changing the girl into a spider, doomed forever to spin webs and dangle precariously.
Arachne
Arachne was an arrogant girl. She thought she was the best at weaving and challenged Minerva (Athena) to a weaving contest. Minerva saw no flaws in her work and became extremely jealous. She beat her over the head with a boxwood spindle and turned her into a spider.
The story of Minerva and Arachne is typically told from a third-person point of view. This allows for an objective narration of the events and the interactions between the characters without being limited to the perspective of a single character.
It is the myth of a young girl boasting that she is a better weaver than the goddess Athena/Minerva. As a result of her boasting, the goddess, disguised as an old women, came to Earth and challenged Arachne. But after Athena saw that Arachne was weeving images of evil, she tore the clothe apart and turned Arachne into a spider.
To explain natural events and why stuff happens the way it does. For example, the story of Arachne and Athena (Minerva) tells why spiders spin webs.
Arachne was a mortal who thought she was better at weaving than Athena. They had a competition, and Arachne's weaving showed gods having affairs, and that really ticked Athena off. So, Athena turned Arachne into a spider.
The legend of Arachne was Greek, not Roman. She did not have a goddess who was her patron. She was challenged into a weaving contest by Athena because she claimed that her weaving skills were better than hers. This got Athena's annoyed. The Roman poet Ovid wrote a version of this Greek myth in which he used the name Pallas Athene, another Greek name for Athena. In his version, Arachne beat the goddess. Pallas Athene struck Arachne on the forehead three or four times. Arachne could not bear this and she hung herself. Pallas Athene brought her back to life, but, as a punishment, transformed her into a spider so that she and her descendants could spin spider webs. The Roman equivalent of Athena was Minerva.