The Birth: Way back when Marvel Comics just came out, there was no Spider-Man, no Hulk or nobody else. The Fantastic Four was the begining of Marvel Comics and was created by Stan "The Man" Lee and Jack "King" Kirby. Stan was the writer and Jack was the artist.
And with this new comic; Fantastic Four #1 (vol 1.) Dr.Reed Richards made his debut. Reed like the other members was just a mere human. He was also one of the top scientists in the US. It all started when an angry Ben Grimm was goaded by Susan Storm into helping Dr. Reed Richards pilot his spaceship. That night, four civilians; Reed Richards, Benjamin Grimm, Johnny Storm and Susan Storm took off in the spaceship Reed Richards had spent years constructing.
Benjamin Grimm may have been an excellent pilot and was steering the ship real smoothly, but fate had other plans for them. Their ship entered the cosmic storm area. Unfortunately for the forsome, their ship needed heavier shielding. The cosmic rays bombarded the ship running right through the ship's passengers, putting all of them into a tizzy. Ben felt too heavy to move and lost his control over the ship. Luckily the ship's autopilot kicked in and steered it to a rough but non-fatal landing.
It was only after the four exited the ship that they realized that the cosmic rays had affected them in a really drastic manner. It was Sue who first displayed signs of the after effect of the cosmic bombardment. She started fading away and then all of a sudden returned to normal. The next to experience the change was Ben. His skin started hardening and turned to an orange color. And then Reed started showing an elastic capability. The last to change was Johnny who started burning up and changed into a human torch
As realization of what had happened started to dawn on them, the forsome decided to use their powers for good. Susan Storm decided to go by the name of The Invisible Girl which later changed into The Invisible Woman.

The Alter Ego: Like the other members Sue never hid the fact that she was The Invisible Woman. Sue was already engaged to Dr. Reed Richards when the accident with the cosmic rays occured. She later got married to him and bore a son named Franklin. After Franklin, Susan was to deliver another baby, but she suffered a misscarriage. Susan Storm Richards is also the elder sister of Johnny Storm.
Initially, not being used to this super-hero stuff, she used to faint from overexerting herself. But later on, as she got more independant and strong, she abandoned her name of Invisible Girl and adopted the title Invisible Woman. And she also became the team leader when Reed had apparently died.

The Legend: Like her name suggests, Sue can turn herself invisible at will. Not only this, she can use the power to turn others invisible as well. Sue is capaple of projecting force-fields which can withastand mighty explosions and pressure. The force-fields are mainly used for protecting herself and by extending it around other people and objects; protecting them as well. She can generate tiny "force spheres" to keep an enemy off balance. This is a power which she rarely uses though, since she thinks it to be a bit too primitive and ineffective. She can also fire small force blasts.
Susan Storm may be the most glamorous member of the team but she has held her ground against many of the world's most earthshaking villains. She has even stood her ground against the Thing when the Thing was mind-controlled by a lady called Karishma. Using her skill she easily thwarted Karishma. When Susan got pregnant with Franklin, she briefly left the team and Cystal of the Inhumans took her place. And later when she was brining up her son, Medusa filled in for her.
When fighting against Ahab, she was changed into one of his hounds to obey his will. Later on, she was cured when Racheal Summers sacrificed herself.

The Fantastic Four #1