In memory of their mom, two sisters continue to remix and re-send the same Mother's Day card to each other every year.NEWARK, Delaware -- Brenda and Donna, two sisters from Delaware, have sent the same Mother's Day card to each other for 20 years.Each time it arrives in their mailbox, they add messages and photos that evoke memories of mom. Both have become mothers themselves. And between them, three of their children serve in the military. Report a correction or typo