Parents:
Vision
Wanda Maximoff

Kids:
Tommy Victor Maximoff
Age: 11
House: Gryffindor
Lover: N/A
Blood Status: Muggleborn

Billy Wallace Maximoff
Age: 11
House: Ravenclaw
Lover: N/A
Blood Status: Muggleborn

Background: billy is more mature than tommy both are young but are great kids

Other family:

Olek Maximoff Grandfather (Deceased)
Iryna Maximoff Grandmother (Deceased)
Pietro Maximoff Uncle
Jessica Maximoff Aunt
Luna Maximoff Cousin 
Paul Maximoff Cousin

Ultron Grandfather (in a way)