Lord Wroxham - a little reality check, how exactly are you posting on here - a 1st Class stamp on a postcard maybe

.
My good lady also refuses to have a mobile but gladly uses mine and I recently snuck her a minimal cost new Google Chrome book and she is a frequent user after the initial denial period. Well worth the £125 on offer from EE at the time as I got my phone back and it does everything and far more than her needs at present and she's big enough to say she finds it useful.
p.s. Many such burner phones will let you down in anger as if you do not use them they drop you off assuming you have snuffed it I imagine. This happened to my MIL's car phone when she wanted it most.