Yes, she can email a self created video/slideshow in iMovie that uses images from her Photos app. In iMovie she just needs to click on File>Share>Email, set the resolution in the dialogue box that appears, click the share button, and wait a couple of minutes for the sharing process to complete. After it completes, a blank email will appear with the movie/slideshow in it, and just needs to have your email address inserted in it for sending.
If the movie is too large, there may be an email attachment size limitation by the email provider service that could prevent the email from sending.
Alternatively, your friend could upload it to You Tube or other video hosting website. Or, give the slide show to you on a thumb drive. If your friend created it for your business, by what method did she plan to send it to you?