If it's not the dos2unix issue, try creating a new script file from scratch -- no copying, etc -- type it in. You could have invisible control characters embedded in there somewhere, depending on your choice of editor. This issue has bitten me before.

Just a security note -- I know it's your wife's laptop -- a better choice for permissions would be 755. Setting permissions to 777 (everyone has full access) is a bad habit. If you ever get a job doing perl CGI scripts or something like that, you'll need to be careful.