Need [flagged-user:mail]

I have code that does flag('flag', $flag_action, $instance->nid, $account) and it does flag the correct user. However, "flagging-user" points to the person that caused that to happen, so the Rules stuff that produces email sends it to the one doing it rather than the person being flagged. I do not see a token for [flagged-user:mail]. I need this email to go to the flagged user; copying the flagging-user would be okay. How can this be done in Rules?