Have little Annie ask everyone he meets for the first time if they are an angel.

Have Anakin do it for the duration of his life thus forging a stronger bond between the PT and OT.

Darth Vader : Are you an Angel? No? Then you are part of the Rebel Alliance and a traitor, take her away!

Imperial Officer: [to Vader] Holding her is dangerous. If word of this gets out, it could generate sympathy for the rebellion in the Senate.

Darth Vader: I have traced the Rebel spies to her. Now she is my only link to finding their secret base.

Imperial Officer: She'll die before she'll tell you anything.

Darth Vader: Leave that to me... Are you an Angel?