Normally a .sig file is a "signature file" created for using with other documents. There are others that use that file extension. What program did she use to create them with? She will need that same program to open and use the file correctly.
File Extension Details for .SIG
Hope this helps.
My wife created some pages for PTO/Sunday School. When she saves and tries to open it says "not a Win32 application". Any help is appreciated. Thanx.