Mi Madres es Culpable

"Mi madre es culpable" as in "My mother is guilty"?

Culpable is an adjective that does not change according to gender, so it's culpable whether you're talking about a male or female. It does change with number, however. So to say "My brothers are guilty" you would say "Mis hermanos son culpables".

2010-09-20: However, culpable is usually used as referring to the phrase "to blame". So, mi madre es culpable is probably: "My mother is to blame".