You are probably right. I always thought taena's inn is some sort of refugee camp, these noble women tries to make a living after being exiled.Because it's quite obvious that "Trueborn" is her word for elf. She doesn't ever call herself an elf, just like Blair doesn't call herself a dwarf, and there is no reason to believe that "non-trueborn elf" is even a thing in her mind. There's no suggestion that the other elf girls are any kind of royalty like she is, but she still says that they should have "trueborn" men rather than human ones.