She might have been a "lead licker" who was an earlier generation soldering expert who used to literally lick the solder. This was forcibly stopped in approx 1980 here but I noticed people doing it when I was working on a line as late as 1995. They were older folk and yes they had the skin problems.

I myself have done a lot of work with leaded solder and have 20 rolls of it in the cupboard and it's most likely zero risk if you take the relevant precautions which are keep it away from eating surfaces, clean your hands afterwards properly, keep things out of your mouth and use a fume extractor.

I noticed analogue "legend" Jim Williams also used to lick the solder and had serious neurological problems when he got older and wondered if there were any links.