That's great - I somehow missed the artistic talent in my family. My Dad was very good, we found a bunch of watercolours when we were clearing the house out. My daughters are talented too.....me, I wish I was. I bought some "how to draw" books and I try but it doesn't come naturally. It must be so relaxing and enjoyable to do what you do!
Sketchbooks are relaxing.
The art I produce is not. It's not easy and relaxing is far from the adjective I'd use. It's a bit different for me though.
I purposefully kept my kids out of arts orientated programs. I know what my life is, I knew how much they'd be exposed to the arts through me and my wife, and really didn't want to pigeon hole them. They're both good artists, writers, actors and musicians and will talk aesthetic theory ... but still hope they just keep that in their back pockets and pursue something else.
As far as drawing. It's easy.
If you can sign your name you have the manual dexterity to draw.
The difficulty is seeing and transferring it to your hand.
The #1 thing I suggest is by the cheapest dollar store sketchbook, an hb pencil you have kicking around... grab a brick. Put it down. 10 second drawings. Turn the brick. 10-20 seconds. Rinse and repeat for half an hour for a few days and you grow accustomed. Then recycle the paper and never think of it again.
When I've taught people how to draw. I talk about speed and that the sketches are disposable. I often use the analogy of a guitarist learning a new song. Those notes he/she are playing are gone. We don't expect it to be recorded. Drawing is no different.