Yes, of course it is!
It is actually good that the broth turned into a gel! That is the difference between bone broth and regular broth. The health benefits of bone broth come from the same ingredients that cause the gelling to happen i.e. the collagen in the bone broth.
Sometimes it will gel more than normal but it is definitely safe to drink. Our bone broth will always thicken when refrigerated and depending on the temperature, it can sometimes thicken to the point that it is actually lumpy. Our bone broth will remain fresh for 7 to 10 days in the fridge.
The sign that it has gone bad will normally be a weird smell or off taste. You can always freeze your remaining bone broth if you don't plan on using it immediately.