Samus Aran is a copyrighted character of Nintendo's Metroid franchise, but she appears in an entirely non-Metroid-canonical capacity heavily in the Epic Quest Saga. In our heap of text we call a story, she is the wife of The Baker, and one of the primary members of The B-Team. All of her Metroid experience holds true to Epic Quest, and as such her memories from the first twenty years would be consistent with her experiences in Metroid canon.
In the first Universe, Samus Aran was a lone bounty hunter that contracted her martial expertise to the Galactic Federation (the major governmental affiliation in the cosmos.) Her early life was marked by intense tragedy: she was the lone survivor of a Space Pirate raid on her home world of K-2L; this happened to her at the age of three. The Chozo discovered her after the destruction of her home, and took her in as one of their own. In order to survive on their harsh planet of Zebes, it was necessary to infuse her with Chozo DNA — this gave her superhuman abilities, including the ability to withstand the Zebesian environment.
For the next eleven years, the Chozo trained her as a warrior, and gave her a modified Power Suit. As she grew and matured, her abilities did as well — she learned to master the Power Suit to some degree, and was given her charge from the Chozo: she was to be the protector of the Galaxy. She went from there to join the Galactic Federation Police special forces, where she increased in ability and maturity.
After that, she lived life as a bounty hunter, fighting for pay.
Several years would have passed since Metroid: Fusion. There was a call for the greatest heroes to fight in the Battle Royale, and she could not refuse. After joining, she stayed rather cautious and secluded, and didn't influence main events until Jacen Solo mind-controlled her to do mischief. From then, she had a few other encounters, finally meeting her future husband, Alexander Jenkins (The Baker). He actually appealed to her instantly, but she did not want to enter into a relationship that would weigh her down, and knew that she would not be able to resist if he lived. So, she killed him. (It is assumed that this extremely out of character action is due to mental stress from Jacen's tampering.)
The Baker had feigned death, and had hijacked and crashed her ship. After some drama in the vacuum of space, the exited The Movie and entered the real universe. (It is then assumed that the events of Metroid happened exclusively in the Movie. This is a fair assumption, seeing as Metroid-related characters only appear during the Movie arch.)
It is after that event that the Five Lost Chapters occurred. Samus met up with the Baker once more, for she was given him as a gift by one of the iterations of G-Zilla. After one last rejection, the Baker slew G-Zilla from lugubriousness; this feat was great enough to change Samus' mind for good. She later married him. From there, they met up with Raynor Zeraph for the first time; New York is destroyed shortly thereafter.
Many years pass after the destruction of the city, in which Samus and the Baker live as mercenaries and grow wealthy. The Baker also sells ChozoMufins on the side at this time, and does so via his Delivery van-ship II. Three years after Guitar Hero's failure at killing The Dragon, they were drawn into the B-Team through the theft of the Baker's Ban-Hammer and Mufins.