Reply To: Best mobile-friendly export method?

Does she need to retain vector data? If not, export it as JPGs or PNGs

For a PDF:
Color: Your images should be RGB, no Spot Colors, no Color Conversion in PDF Export, and Export as newest Acrobat version.
If you have a lot of images that are scaled down in InDesign, you should try scaling the images (in Photoshop, etc) down and re-importing so they’re close to 100% in InDesign.

Hard to tell without seeing it, but sometimes saving all your vector data as JPG or PNG, then placing them back in behind your text will get the file size down.