I failed to read all of the replies, but just so you know,
Here is why!
This privacy act is in place to protect your child. You should calmly contact Google and give them your WRITTEN CONSENT to allow her to use Google+. I believe, according the all the legal jargon in that link, children are not allowed to have any sort of memberships (accounts, whether it be email, forums, gaming etc) UNLESS a parent gives consent. If you are calm about the way you proceed getting this account back, you really shouldn't have any issues with Google reinstating her email address.
Google is only following law, they are not trying to make your life hell. What other company gives their workers payed NAP time?