With knitting, one needle is held more stationary than the other. The stationary needle holds the stitches and the second needle is moved to create the next row of stitches. As I was thinking that her week side would not be able to press the needle to her side we started holding the stationary needle between our legs. In another hour she had about four to six rows of knitting done. When I got home my husband and I toss around ideas for holding the stationary needle and I also put the question to a wonderful on line knitting group called Ravelry. More idea seeds were planted. One idea was to check out a web sight that showed a clamp tool holding the crochet hook stationary. The light bulb lit. You don't have to move the crochet hook you can just move the yarn. Pondering this I walked passed my oil painting supplies including a grass place mat I had rolled up to stick my paint brushes in. Two and two came together to make four. By itself the rolled grass or reed place mat, rolled and held tight by rubber bands was easier to hold between my legs and held the needle or crochet hook nicely, if maybe a bit loose. I practiced knitting till I could cast on using a knitted cast on, knit, purl and make yarn overs with one hand. Then I set the knitting needles aside and tied my hand, I know pun pun pun, at crocheting. Practice with crocheting gained me skill in single chaining, and single crochet. The crochet hook did wiggle a bit more than I wanted. Today I raided the local thrift stores for something that would improve on the reed place mat roll. I found two webbed rubbery place mats. I have similar material at Walmart for lining drawers. Nice grippy stuff. I also bought two long belts. When rolled by its self the webbed rubbery mats were hard to stick the knobby end of the knitting needle in. So I tried rolling the rubberized mat inside the grass mat. This although harder to slip the knobby end of the knitting needle in then just the grass mat, did hold both the knitting needle and crochet hook quite solidly. The belts would be used to hold the rolled mat at her waist, or maybe to the arm of a chair.
I suggest that you find at least an intermediate knitter and crocheter to help. Check the web for clips on how to until you find one that you or you and your friend can understand the best. I use this system at the library. I pull books, sample them and check out the ones that I understand best. My computer is rather old and doesn't do U. tube and I would so like to check out that u tube, and this one and oh oh oh so many.
For me there is a tail end of a ball or skein of yarn which is the end of the yarn. There is also the skein end which is attached and disappears to the skein or ball of yarn.
So here is how it stands. To get started or to help someone get started, find some sort of material to use similar to my rolled place mat. Don't forget something to keep it from unrolling. Hold this between your legs. Place one knitting needle's knob end into the roll. Make a slip knot, place this slip knot over the tip this stationary needle or what I think of as a holding needle. If knitted cast ons are new to you check out the web or books on how to do a knitted cast on.
I would start with 10 or 12 stitches. To knit you will move the working needle, the one you move with your hand, up the holding needle or the one that has the 10 or so stitches on it and is held in the rolled grass mat, then tuck the knob end of the working needle at your waist, I have a bit of a inner tube which does a grand job of this, while you move the yarn around the working needle to continue the knitted stitch. To purl you will move the working needle down the holding needle and through a loop. As with all things practice is needed.
For crocheting stick the crochet hook in the grass mat roll. Run the yarn under the good leg to the crochet hook. Come to think on it this might add some yarn tension control for knitting as well. Make a slip knot and place it over the tip of the crochet hook. Slide the slip knot down the crochet hook a bit. Take the yarn that leads to the skein and make a loop around the crochet hook. pull on the skein end of the yarn which is to the outer side of the leg, to hold the new loop in place. take your fingers and pull the slip knot up past the new loop and off the hook. The first chain is made. Continue in this manner until you have a chain of 10 or so stitches. To make the second row pick up the chain and poke the second or third chain, remember this is a first time thing so go for ease and when you have a good system you and your friend re-fine it, and poke the tip of the hook through one of its loops. You should now have two loops on the hook. Make a third loopfrom the skein yarn, around the hook as you did for making the chain. pull the middle loop up over the new loop and off the hook. Make an other new loop around the hook above the others. Now pull both the middle and the lowest loops, one at a time, up over the top hook and off the hook. Your first single crochet stitch is done. Poke the point of the hook through the next chains loop and continue single crocheting to the end of the chain. Your firs row of single crochet stitches is done. Chain to loops as you did in the beginning and poke the tip of your hook through the single crochet stitch closest to the hook and single chain across.
For all you who don't stop when you meet with such a challenge as my friend has, my hat is off to you. To those of you that searched out any solution, I hope this will help. My friend and I have had one two hour session. Our next session is this coming Tuesday. So I'll let you know how it goes. My mom would say when we would see a handy-caped person, "There but for the grace of God go I" and now I think with, with grace of God I can help.