I found that using an upgraded Artemis's 'Green Storm' (RT + B) power was the best way to beat her. I was only level 10 when I faced her for the first time and I had 5 or 6 hero points on that ability with two WayneTech Enhancements: Dr. Fate's Master Energy Control Medallion and Titanium Bow. These aren't necessary but they might speed up the fight a little.
Also, to make it quicker, have Nightwing in your party with 'Multi-Batarang' upgraded (RT + X) and switch off between those two when you run low on power with one of them.
While fighting Killer Frost, don't worry about the mechanical spiders. They're very easy to kill and don't have anything to do with the boss other than a distraction. Your team mates should have no problem taking care of them and if not, your powers should kill them in a shot or two.
Just get close to Killer Frost and use Green Storm/Multi-Batarang as much as possible. Be aware of when the ground lights up to dodge her ice attacks that come from the ground and from above and you should be fine.