Charles:
Remy LeBeau or Gambit. You lost sight of each other at a very young age. You know you have a brother but if he is still alive you don't know.

Erik:
Thor Odinson. Yes you are the sister of an god but you don't know it. When you were young Frigga thought you magic but when Asgard was attached one day you got lost in the fight, fell to 'midgard' or earth and lost your memories. Your powers stayed but your immortality was lost. Never said you were an mutant.

Hank:
Jean gray is your younger niece. She is still 2 at the time but she is so very cute. Hank once went with you to visit her. Hank quickly found out that she was a mutant to. Jean had him pinned to the ceiling.

Sean:
Warren Worthington is your younger brother. You know he is a mutant like you but that is all you know. You lost contact after you joined the team. Charles promised you to get him to the mansion but there are some complications.

Alex:
Tony Stark. Yep your brother is the most popular billionaire playboy of the planet. He isn't a mutant though. Your the muggle born of the family...

Pietro:
Pieter Quill. You were still to young when he disappeared. After your mom died you lived with your uncle. Where your brother is you don't know but you hope to see him again. Your no mutant but an alien. More alien then Pietro will ever be.