I also have a crooked beak hen. I hatched her April 1st along 14 others. Her beak started showing signs of deformity at 3 weeks but she was a tough little cookie so we decided to leave her be and see what happens.
At about 3 months it was obvious that she wasn't getting enough food so we put out a deep bowl of food mixed with water and a deep bowl of water too. She was getting some but no where near enough. My vet had previously given me some Lafeber's Nutritional Support for a chick that got sick at 3 weeks and she bounced back in no time. I did a bit of research on the food along with my vet and we figured it would be good to give to our crooked beak, along with baby food of pureed (how do you spell that? It doesn't looked right somehow?) peas, green beans, apples and peaches. We feed her 4 times a day. She'll eat a whole scoop of the Lafeber's mixed with the right amount of water and a full tub of the baby food in one meal. Evening meal, I try to get a little more down her just to make sure she satys warm through the night chill. She sits on my knee while I feed her and when she's had enough, she'll jump down and off she goes, back to the flock.
It was hard for both of us to adapt to syringe feeding, me being new to keeping chickens and her working hard to trust me. At first, she'd move her head away and I'd squirt the food in her eye or something. It would also drip down her chest feathers and the others would pull them out, so I then washed her down after every meal and dried her off. She now comes to the door when she's hungry and we have it off to a tee! It all goes straight in her beak and we don't need to wash her off anymore. I also get her beak filed at the vets every 3/4 weeks. I've just ordered a couple of sweaters (yes.....they make chicken sweaters) for her to help keep her warm during the winter months, however, someone on here said they weren't sure if that was a good idea because the sweater would compress her feathers which are the best insulater she has, so I'm doing more research on that. It's a lot of work taking care of this little hen, but she it worth it to me and my kids. We absolutely love and adore this little girl and will do whatever it takes to keep her happy and healthy.