Don't underestimate your mum. I'm 65 years old and have tried cartos, carto tanks, vivi novas, EVODS and now using the Kanger Aerotank. I did all of my own research and ordered my equipment knowing it may not work out.
My advice is to get her a variable voltage eGo or spinner battery and EVODs. This set up is what I call "fill and vape" and does not require fiddling. The only think you have to explain to her is ohms and voltage. If she can't see well, get her a magnifying glass and a lamp she can use (if she doesn't have one).
I'm so glad she's interested. Don't show your doubts to her, let her be the one to decide if it's too much for her. She may surprise you. And, btw, I smoked for more than 40 years, 1 1/2 packs of cigarettes a day. I've been smoke free for 2 years and the transition was totally seamless, no will power involved at all.
Good luck to both of you.
I'm even older than you, RosaJ,
The Evod clearomizers are very reasonably priced, about $5, so you can get several of them, and have them all filled and ready for your mom to use. I have pretty good vision for my age, but do use reading glasses. I don't have trouble filling the Evods myself when I have them in good light.
Glad your mom is interested and I wish you both well.