Hello and welcome to the forum. We have a few threads on diet for renal disease in dogs. You can find them by using the search box at the top left of the page.
Your dog’s appetite might be diminished because of the build up of toxins in her blood. I am wondering if your vet could give her some palliative treatment. Perhaps an anti emetic, given half an hour before food would help. Other drugs that might help are vitamin B12 given by injection, a small dose of steroids, Ranitidine and perhaps a course of antibiotics if there is an infection. It's all about helping the dog to feel better. It might be worth discussing this with your vet.
First of all, if the yoghurt is flavoured be aware that it could contain xylitol which is toxic to dogs. Plain yoghurt can be given. Many dogs tolerate milk products but some cannot.
You want to prevent dehydration so dry food is probably best avoided unless soaked first. Usually low protein is suggested but just as import is the quality and digestibility of the protein source.
Your idea of home cooking is a good one. Dogs generally enjoy home cooked food, not least because of the aroma. Appetite is stimulated by smell. It can be difficult to get the balance of nutrients right so I am wondering if Pure Vegi Plus Mixer
might help. You could then add the protein of your choice. Steamed white fish is digestible, as is cooked egg and chicken. All are excellent sources of protein. The company has a helpline so if interested, give them a call. Carbohydrates that might be useful are sweet potato and butternut squash. I usually cook the former in the microwave until it is really soft then mash it up.
We have plenty of information in our Home cooking for dogs section.
One website mentioned there is American - Balance IT.
They provide recipes for specific diseases but you would need to discuss with your vet first because there are different dietary requirements depending upon the nature of the renal disease. It's helpful to ask the vet what to look for in nutrition terms eg protein/fat etc.
Regarding prescription diets, they can be useful particularly in the short term. David has written an article about them here.
Royal Canin Renal Dry has low protein, 14%. They can be worth trying but best to get samples if possible because some dogs are not keen on the food. AFAIK there are no commercial foods that have protein this low. Most of the low protein foods are dry so would need to be soaked. They usually come in the weight control/light categories.