My little DGD (Zippie) wanted to help me sew since she was 2. I put her tall chair next to mine. I taught her how and when to press the start and stop button; reverse and the locking stitch; and the thread cutting button. Many times she'd opt to help me sew rather than play.
Then I hatched the idea of my DGD, my DD and I sewing a quilt together for my dad. So I picked out a very simple pattern and Zippie at 2 1/2 helped me sew the top of the quilt for her great-grampa. I was amazed at her attention span. My DD couldn't help - she broke her elbow in 2 places tripping over the cow (Zippie's riding toy).
I just put the binding on the quilt and need to hand sew it.
My SIL captured photos of Zip and I sewing with DD in the background. We're going to make a label - 3 generations sewing for the fourth - and give it to my dad for Father's Day.
The funniest part is Zippie knows more about sewing than my daughter! It's cute when Zip shows her mom what to do.
I've thought about buying her a little sewing machine for her 3rd birthday (on July 4th) but decided she'd get bored with a little machine - she's too use to my Janome 6600.
If they show interest it's up to us to take them serious and teach them what is appropriate for their dexterity and age level. Each child is different. And all we need is patience. Start slow - let them learn one or two things at a time. And make it fun. It's their first experience sewing and we need to be encouraging.
HAVE FUN!