no she only had 2 sisters Stheno and Euryale and her parents were Phorcy and ceto
Heracles did not "defeat" any of Medusa's brothers and sisters, for they were immortal. Further, the mortal man who killed Medusa with aide of Athena was Perseus - not Heracles.
Medusa had no brothers but had 2 sisters named Sentheno and Euryale
Medusa did not, no.
snakes
Medusa did not control any area. She is not a goddess. If she was, she would control something.
None. Athena cursed Medusa that she couldn't have any children or marry anyone.
Some say that Pegasus jumped out of Medusa's blood after her head was cut off. In these versions, Pegasus was said to be the son of Medusa and Poseidon.
3 actually
yes athina
Medusa really didn't have any responsibilities. She was a monster that turned people to stone whenever they looked at her.
A medusa looks like an umbrella and a polyp any idea!
No: none that were mentioned in Greek Myth.