Well, when we were young boys learnt woodwork & metal work, girls were taught to cook - division of labour (or sexism, depending on your viewpoint). And the girls who didn't pass the 11 plus exam to go to Grammar school also learnt laundry skills with the idea that girls would stay at home and be in charge of childcare and the day-to-day drudgery, men would be wage earners and do the handyman jobs as they arose.
Glad your DIL is taking an interest, you will still have an excuse to visit, when you've trained her you can start the scientific and practical education of your grandson. When I ran a Playgroup for 3-5 yr olds the proper use of hammers and saws was a regular activity, and occasionally we spent a week exploring bulbs, wires & batteries in very small groups.

I think to teach her you need to decide first what her basic tool kit should be.
Then get into the habit of giving a running commentary of what you are doing. And the thinking behind it. There must be a lot that you do automatically because you know that something is an A type not a B.
Or just stand back and give step by step instructions.

Then start planning the Christmas present kids workbench (to be used under strict supervision only - "tools not toys"). One of the things I had to stress with preschool children was to saw without too much pressure - "like stroking a cat". I should think using the right amount of force, not too much, is one of the skills all good DIYer has learnt to do instinctively. Not ruining the slot of a screw etc.