My child's account is not working. The teacher nor her are able to activate her account to work properly, making it impossible for her to complete assignments. She received a new password but could not reset because she could not remember her old password.
I'm a bit confused. Duolingo accounts don't need to be activated - your daughter can just log in and start using it. If she's received a new password, she doesn't need to reset it, she just needs to log in. If she's used the password reset mechanism, she doesn't need the old password or the new one, she just needs to check her email.
Can you tell us what happens when she tries to log in, using the username and password her teacher has given her?