The first Icemaiden (Sigrid Nansen) in two costumes on the left.
And Icemaiden II (Tora Olafsdotter) on the right, who was named later on only Ice.
1. Icemaiden I (Sigrid) as a member of the Global Guardians
....at her first appearance in Infinity Inc. 32 
2. Icemaiden I (Sigrid) when she joined the JLA after Ice's death around 1995
3. Icemaiden II (Tora) as member of the Global Guardians
.... at her first appearance in Justice League International 12 
4. Ice (Tora) as a member of Justice League America around 1992
There was much confusion about the two very similar characters. But as revealed in Wikipedia about the publication history there has been some confusion at DC editors too, which caused the existence of a second Icemaiden.