Possible Identity Theft - Please Advise!

Hello,

My Mother made a copy in a liquor store of a document she needed for
the unemployment office.  She made the mistake of leaving the original
in the copier when she left, and the paper has her social security
number, name, address and everything on it.  She went back to the
store later and there was no sign of it.  I'm really afraid that
someone took it and will now use the info to open accounts and ruin
her credit.  Is there anything she can do BEFORE anything happens,
like alert the credit agencies, her creditors, or something?

Please advise, I'm worried sick about this.

Thanks,
Zoe