Pull up a Client Summary and click the print. That will open a preview window (which looks like this image below), hit the orange print again.
That will open your computers print dialogue window which looks like this.
On the left side of this dialogue box, you should have an option to 'print to pdf' or 'save as pdf' or "Open PDF in Preview". Choose on of those options which converts your Client Summary to a PDF document. Be sure to save it somewhere easy to access. You will now have a pdf that you can attach to an email to your client.