[ThePadawan]

How would my mom find it?

She knows that the green Whatsapp logo is for talking to her friends.

She probably wouldn't click the envelope looking thing.

(I'm not being facetious - IMO HN readers massively overestimate user capability.)

[squeaky-clean]

I agree completely. My mom still doesn't really understand the difference between phone calls, calls over Facebook Messenger, and calls over FaceTime