Fledgling Jackdaw not safe

3 days ago a fledgling Jackdaw was trapped in my chimney for a few hours, it finally came all the way down to land on drying out logs in my non working fireplace. It could not get out without rescue as the logs filled the fireplace. It had some head baldness.

It willingly went into a box. It was set free, but clearly could not get any height in flight. It was stressed & tired too. Parents & it's family were calling, circling. We left it to its family to look after it. During the rest of the day it was on my neighbours doorstep or under his Van. It was semi safe. Cats & other predators increasing. 

At teatime we took it in, friend had a good cage & fed it with mealworm. Day 2, set it free, its family again were there. . It was rested and flew higher. But then we found it back on the ground. Again left it hoping it's parents would keep it safe & feed it. Later it was gone, thought all was well. Another neighbour reported it flew into their window, it survived last night, found again today on the ground, very exposed to predators. It was clearly weakened & distressed. No doubt likely to be killed. Parents still circling & calling.

It's been taken in, I have him/her. It has drunk, eaten a worm and some crumbled food, just about. It.looks relaxed and has settled in the straw and gone to sleep.

I cannot try and release it again, so need advice on how to look after it. After the fight it has put up this little fighter should live. 

Really tried to leave it, but it has not worked.