Wow, that contains a fatal weakness (no pun intended), that She won't assume the email is spam (or a scam) and just delete it without opening it.
It's quite possible for you (or anyone who uses your work) to have the outcome they were trying to prevent because of this.
She knows about it, so she will actually be expecting it.
But yes, that is indeed a risk, particularly for other family members who don't know there is an email for them.