Clara Blaze is a fake name for Johnny Blaze's mother. Although it is clear that Naomi Kale is Blaze's mother (and Barton Blaze's wife), it is also clear that Blaze believes his mother's name is Clara. The best explanation is that Crash Simpson lied to Blaze about his mother's name in order to protect him (since he seems determined to make sure that Blaze and his mother never meet).