Sorry I am so late to this thread. First I do hope Jemma is feeling better, I know how awful it is to be worrying so over a beloved kitty.
I am going to be backing up Lola here on the Hills junk. The dry has NO MEAT in it at all. It's a terrible food and, with the lack of meat, not to mention the reduced protein, she is heading for illness much worse than kidney disease. Cats on these "diets" don't die from kidney failure, they die from muscle wasting and protein starvation.
The lack of moisture is also going to compromise her kidneys.
You can research foods that have lower phosphorus and you can use a phosphorous binder. Have you been to any of the ckd sites? Sometimes when a cat gets CKD it's a genetic predisposition. Acute kidney failure of course is a whole different thing, and if caught in time is sometimes reversible, depending on the cause.
I urge you, urgently, to ditch the Hills k/d kibble. It's a terrible thing to give a cat. Vets should be ashamed to sell it let alone recommend it.
Is she being given sub q fluids?
As for feeding the cats on a schedule, it's not all that hard to do really. It may seem like an overwhelming task, but the main issue is your own mental approach. Just make up your mind that this is going to happen, and do it.
Incidentally, some believe (including myself) that, aside form how bad dry is to begin with, free feeding is very bad for cats, for a few reasons.
Bad for the kidneys: Every time a cat smells food the kidneys go into action, and prepare to work. Even if the cat doesn't eat, the kidneys are working. That's a lot of unnecessary stress on the kidneys. Along the same lines, it is thought to be bad for the urinary tract.
Cats, being carnivores, need their stomachs to be emptied periodically, to keep their motility working properly. The stomach needs to be emptied of food, and the cat needs to feel hunger, to get the other stuff out of the stomach. For a house cat this means fur. For a cat "in the wild" it works this way because carnivores eat a lot of stuff, including feathers and fur of their prey. This stuff also has to be moved out. So their bodies are designed to digest and empty the food, then a few hours later, as they start to get hungry, the other stuff moves through. Then off they go to hunt again.
Having said all that, I do hope Jemma is doing better.