My mom had square blocks of different colors already cut out then let my kids pick which colors they wanted to use. They loved picking their colors and the simple lines were enough for them to get used to the sewing machine.

The kids want to do the 'big fun' stuff first so let them start by using the machine, if nothing but lowering the pressure foot for you.

These are some of the things my kids do-
cut fringes off washed FQ
glue scraps onto pieces of paper (for toddlers)
sew on the sewing machine their own doll quilt (if they are very small they sit on my lap)
hand me pieces of fabric I need to iron
sort and fold
help with basting

My now 13 yr old is an avid quilter and she made her first quilt at around three. With my help ofcourse. Others make their first quilt when they are older. It all depends on how precise they are. Also I have them tie quilts well before they do quilting. I found hand sewing much harder then machine sewing for them to do.

Rotary cutting is the last thing I let them do. Now at 13 I let DD rotary cut under my watchful eye. I had a friend whose 10 yr old sister cut herself with a rotary cutter at a class at Quilt in a Day. Just not worth it to me.

Besure to do it all in small increments spaced over time. that way they keep enjoying quilting. do not forget their snacks and some of mom's/gram's chocolate treats.

my (almost) 2 year old loves to color on white fabric with fabric markers. She "draws" all sorts. We have laminate floors in the house and I cut out 12 or 14 inch squares and use painters tape to tape them to the floor so they don't move when she colors them. I don't allow food or drink in my sewing area - we always take a "break" every half hour - that's my daughters attention span to coloring.

my granddaughters started at 4 (they had already been collecting fabrics and had a good stash :)
i picked up a little singer machine and a little carebear table and chairs so they had work area that worked for them...not trying to deal with my (over-size to them) machine and table.
i did all cutting and pressing; they would lay their fabrics out on the floor, arrange them how ever they wanted and then start sewing them together. i did not take any of the joy of their accomplishments from them by critizing ; they only received praise even when a seam was 2" wide. their project! each girl made a very special quilt for their daddy who is in the military. i even turned a dresser on it's side for them to stand on so they could quilt their own quilts on the long-arm...all 3 of them (now 15, 14 & 10) still sew, and are quite good! the middle child designs purses for her friends and is an awesome hand embroiderer. the oldest makes quilts, the youngest makes pillows and fun stuff...they love to create!
my biggest tip (and lots of people whole-heartedly disagree) is don't sweat the small stuff, let them create without criticism...anything can be (fixed- out of site) to make it work and they feel so (empowered) when they finish that pillow, quilt, rice bag; what ever. keep things (kid-sized) so they do not have difficulties reaching. and let them create. you will learn lots from them.
and as for the stash...my youngest gd is the (worst) when it comes to fabric (really takes after her grandma) if they go to any store and it sells fabric she will not leave the store without a piece (at least a fq) she has been feeding her stash since she was about 2 1/2. when ever the girlcome to visit they know that my fabric shelves are free-they can use anything at all they want to as long as they are making something and not being wasteful...well that youngest girl one time she had a fabric in her stash i wanted to use a little piece of...i helped my self, she wasn't there...used a 4" square from a yard of fabric...well i will tell you what; i was in big trouble when she saw the quilt i used a piece of her fabric in! she knew right away and let me know, her stash was not there for anyone to just paw through! i responded with ... you help yourself to my fabric all the time and i only used a little piece. she said...well you can buy fabric when ever you want...i have to talk my mother into it, and that's not easy!
so, i grin and help their stashes...and i buy my own :)

for my 7yr old nephew and 4 year old niece I had them pick out fabric they wanted and "measure" how much they needed to fit on a pillow form.
Then I sat at the machine and had them stand and operate the foot control (with the speed low) saying "go" "stop". Was the perfect level for them for a first project. Then we made puppets the same way, and once they were sewed they colored the puppet faces with fabric markers. They were supposed to color the whole puppet but they decided they wanted to cut and sew clothes, a hat and hair, I used the needle to put yarn on for hair but had them tie the knots and cut it the length they wanted.

I went in to my son's third grade class to show them some quilts and teach them some basic stuff. I took graph paper for them to design some blocks and I had some "cheater cloth" with quilted designs printed that I had sandwiched with backing and batting. I had pre- threaded needles and showed them how to hand quilt. They LOVED it - especially the boys. Their gym class was after this, and the gym teacher actually had to come and find the class because they didn't want to stop quilting!

Many years ago as part of the "Art Ladies" for our school we did a program on quilts and had cut out many shapes and sizes and colors of construction paper for the kids to make a quilt square picture. They were amazed that they all had the same colors and shapes to choose from but the final pictures were all so different. With so many students we couldn't use real fabric, but the idea worked.

Jane,
I hope you will share pictures of these quilts when they are completed. I'm sure the kids & parents will feel especially blessed by both you and the kids creations! Sounds like fun!!

My 4 1/2 year old is starting quilting this fall. she has a nice selection of scraps all sorted out and ready to go. we plan to make a string quilt. luckily, my viking has speed control so i have her on the lowest speed. i put the foot pedal up on a stool for her to reach. i'll do any cutting for now. she can probably help press things if i lower the iron board way down for her. just be creative and let the child show you how much they can handle.

side note - Jane, you are amazing. great ideas! 4 at a time that qualifies you for saint hood!