Soft in that they still hold their form, but can be crushed w/ the back of a spoon. Brittle might be a better term? Only some of mine got that soft, and they were probably the bones that I saved from crock pot meals (so they already had had a full day in the crockpot before going in for broth). I gave the harder ones to the dog, and she was able to eat them in a minute, so they were definitely softer than a regular cooked bone.
If you ever do a chicken, their bones get soft in 24 hours or less. Once, I strained off the broth and put the bones in the blender w/ a little broth because I thought that's what you're supposed to do. I tried adding some of the resulting sludge to soups, etc. and it was gross. Way too gritty