Data breach?

mama.a

Hi everyone
I don't think I've posted in the right place 
But I know some members will be able to advise me on my situation 

A family member today notified me that her child's ehcp decision had come through via email
She opened it and saw my name address ect
Then my sons name and address 
Then went on to discuss in the letter how long it would take for the final decision would take and the process in which the ehcp pathway works 
The issues I have here is my son as a ehcp it was awarded a year ago 
I don't really speak with my sister so was shocked to see she had sent me all of this 
All other emails from the local authority have been addressed to hef and her child 
So she was confused to see it all addressed to me and my son
The local authority have broken data protection a while back and I did complain and also was given a large sum of money due to it being social care records that they gave to someone
I'm not sure if this needs to be taken that seriously or not so thought I would come here and ask is this a breach of data protection and should I make a complaint or just let this be forgotten about

Thank you 

Aylesbury_Duck

Yes, it's a breach and yes you should report it to the local authority.   It's serious because in some circumstances this could have quite serious consequences.