Tonks is 1/2 blood, her pureblood mother made her related to Sirius (his favorite cousin Andromeda was her mom), but her mom married a muggle Ted Tonks....

As well as (I had forgotten) Narcissa Malfoy was related to Sirius.

Hmmmm... I thought all of Sirius' family were dark wizards but him... forgot about Tonks' mom. (assuming she isn't since she was Sirius' favortie cousin)

Amy

No, Tonks' mom's name was removed from the tapestry (as was his) because they weren't following the family ideal of only pureblood wizards/witches. The Weasley's are actually distant relatives too, but Sirius's mom had removed their names too.

Just got done the OOP myself and can't believe how much i had forgotten myself. :)