You can send her a link to the For the Skeptics on YouTube. As I understand it, that field was designed to “convince” people new to these fields.
I don’t know if WhatsApp changes the file (compresses or whatnot) as it sends the file through its system. Compression and other forms of file manipulation would change the field.
You can send a field as an email attachment.
Keep in mind that quite a number of the fields now have “protection” placed upon them. That protection is often discussed in the description of the field as well as in the thread for that field on this forum. You might want to check your field to see if it has such protection as well as the particulars of your field’s protection. Sending your sister a field that was inactivated for her due to a protection violation wouldn’t really “convince” her, would it? 