The nerdlet has issues with pants. In lengths she wears an 8 or 10 depending on the pants, but she has a waist of 19 1/2 inches (49 centimeters). In addition to this, like a lot of kids on the spectrum, she has tactile sensory issues which makes clothing difficult in general. Mostly she likes to wear knit fabrics, but she will wear other clothing if it is both loose and soft. If all that were not enough, she loves colors and patterns so while I have been able to buy leggings for her and just sew in the waist, it was tolerable to her and nothing more. She recently requested for me to make her flannel pajama pants (which are 4T but she is still wearing) in other fabrics.
So I decided to start with a pajama pants pattern. I chose Ottobre 4/2005-10. I went with a size 128 to start with. I knew they would be short but I figured that the first pair would be just to try out. I chose a lightweight denim that I got from from my MIL. Other than the length I changed nothing. they ended up being really big. Luckily Darth Monkey, who is 3 years younger, is significantly larger in every way but height (though she might match her in the next year in height). You'll have to excuse her pose. I'll admit I didn't make her change it.
I actually have a hard time fitting Darth Monkey's butt into normal pants so I might just use these as a jumping off pattern for pants made for her. The front would need a bunch of excess fabric removed.
So after trying on the above pair, the nerdlet expressed that she wanted to wear them lower and she wanted a waist band, too. I added 14 inches to the length and removed 5 inches from the top (an inch or so too much) and added a long waist band. She's wearing them now, but I think they still need some adjustments for the next iteration.
If it wasn't winter, I might have a field day making her batik and other light cotton fabrics. As it is I'll have to go through my fabrics to find something appropriate. This particular fabric I've had forever and I made a fantastic skirt for my mom with it about a decade or so ago.