Timmain is the "Memory" of the High-Ones and direct ancestral mother of the Wolfriders, and indirectly, some of the Go-Backs as well.  Her only lifemate was Adya who was killed upon their arrival.   
 
Timmain was a shapeshifter and in her wolf guise, befinded the local wolf packs, thus allowing her to defeat Haken and sire the first chief of the Wolfriders, Timmorn YellowEyes by a male wolf.  She also seams to have had a daughter with Aerth who loved her.  It's speculated this daughter may be Rellah. 
 
For a long time Timmain lived as a wolf and remained thus until the Shards series when she transformed to combat Winnowill.  Afterwards, Timmain remained as a white wolf bonded with Skywise. 
 
In recent series, mainly The Searcher and the Sword and The Discovery, Timmain is in her true elf form wearing nothing but her hair as a garment.