Alright, so I just got Gloradin. Server went down yesterday and so I kept track of the server uptime with the /up command. She spawned at 17:50 or so into the server up time, hope this helps!
Gloradin Coldheart (the correct name for this mob) is no longer on a 24 hr spawn (confirmed by myself over the past few days.) She appears to be somewhere in the neighborhood of 30-32 hrs now. I'm guessing they switched this to prevent her getting locked into spawning for a particular time zone.
Unlike the rest of the dwarves in the Glacierbane camp who bounce back after about 20 minutes, Gloradin won't return for 24 hours once she's killed. This is a problem, because not only is there demand for her among people doing their Coldain rings, but giant faction hunters frequently knock her off.
She spawns in the hut next to the guy you start the ring quest with. The only time i saw here spawn was when the entire camp got wiped out when I turned in the Rygor invasion plans part of the quest.