She is a centaur of draconic decent, and quite rebellious compared to her tribe (she respected nature, but didnt want to be a "nature-freak", drawn to the city lifestyle).
Her family has always been abnormal within her tribe, since their blood had been mixed with dragons. But only a single member of the family within each generation carried the draconic traits, suggesting there is a magic spell involved. Normally they became shamans or magic users within the tribe.
The tattoos on Alyk's arms are somewhat of a heirloom passed down to one carrying the draconic traits, upon death of the previous "owner", since they aren't really tattoos, but magical familiars that hide on the body as tattoos until summoned, and the colors are actually scales up close.