This is my sister's char. bio.

First off, your character has special eyes, is a non-canon relative, and where most characters have one main power or a secondary power, or a primary power enabled by a secondary power, your character has three, and manifests none of the frailties that the other X-Men have. On top of that, you're attempting to shroud her past in mystery, which, while it may seem cool or neat at first, giving no explanation as to why or how tends to aggravate the issue; there are two ends to that scale, overexplaining, and underexplaining. Erroring on either side can be fatal; many times a poorly thought-out explanation can be even worse than no explanation at all.

Under the specification TGD-SPC-MS101, by:
                  (a) creating a non-canon younger sister to a canon character undermines the role of a canon character, Kitty Pryde, who fills the role of a younger sister to some of the older cast;
                  (b) copy-catting the relatively unique powers of a canon character, and thereby marginalizing them;
                  (c) bringing in more powers than normal and not suffering frailties, this breaks a limit that can be logically inferred from canon, which destroys your character's credibility;
                  (d) giving your character an eye colour/hair combination that is not natural to the universe it is in breaks consistency of the story with the rules imposed by the setting;
                  (e) not justifying or reasonably explaining who your character is, their personality, what makes them unique as a character, or giving any sort of features besides what they appear as and what they can do destroys the integrity of the character itself;
         you have created a Mary Sue.

I suggest building a new character, one that doesn't explicitly depend on the presence of canon characters. It is quite possible (and advisable) to take this approach, and still make your character special. However, the way you'll want to make them special is by their personality and evolution throughout the series as a character. More importantly, you'll also want to show how your character acts and the choices he or she makes when under pressure or in the face of meaningful challenges.