If you don't have your Ice Minion yet, that means you've skipped a side quest somewhere in Krokotopia or even earlier.
Go through your spellbook and note which of these spells you do NOT have. The side-quests you need to get the spells are listed beside them.
Freeze Ice Trap, level 7 - Introduction to Ice Ice Prism, level 12 - No More Mr. Ice Guy Ice Armor, level 18 - Ice Man Cometh, Going Ice Skating Steal Ward Frost Bite Ice Guardian, level 28 - Gathering Information, the Chest Awaits, Chilling Information Legion Shield, level 35 - I Know a Guy, Thief of Spells (NOTE: You must quest thru Grizzleheim to Mirkholm for this) Ice Blade, level 38 - Fungus Among Us, Removing Toxins, Ice Creature Feature Frost Giant, level 48 - Troll Bridge, Frost Giant's Potter, Kiln or Be Kiln, Horn of Winter Frozen Armor, level 55 - The Spell Trade, The Ruindown (NOTE: You must quest thru all of Grizzleheim and thru Wintertusk to Sudriland for this)
Most particularly pay attention to the bold-typed spells, as they all come from side quests and you have to do them all in order to earn all spells higher than level 42. Also, be sure you quest through both Grizzleheim and Wintertusk - all of your future utility spells and school pets will remain locked until you finish all of the bolded side spell quests listed above.
Alia Misthaven, 120
Fiona Frostweaver, 74