Harry Potter:
same year
Ron twin sister
Pureblood
Gryffindor
no quidditch player
Ron Weasley:
2 years older (same year as the twins)
Oliver Wood, little sister
Pureblood
Hufflepuff
keeper
Draco Malfoy:
1 year younger
Tom Riddle daughter
half-blood
Ravenclaw
chaser
Fred Weasley:
same year
Draco Malfoy older sister
Pureblood
Slytherin
beater
George Weasley:
2 years younger (same year as Harry/Ron)
Harry Potter twin
Half-Blood
Hufflepuff
no quidditch player
Cedric Diggory:
1 year older
Hermione Granger sister
Muggleborn
Gryffindor
chaser
Oliver Wood:
3 years younger
Cedric Diggory little sister
Pureblood
Hufflepuff
seeker
Newt Scamander:
same year
no particular siblings
Muggleborn
Ravenclaw
beater
Tom Riddle:
2 years younger
no particular sibling
Pureblood
Ravenclaw
seeker
Sirius Black:
1 year older
Lily Evans older sister
Muggleborn
Gryffindor
keeper
James Potter:
same year
Sirius Black twin
Pureblood
Slytherin
no quidditch player
Remus Lupin:
2 years younger
James Potter younger sister
Pureblood
Slytherin
beater