I think my inquisitor would be REvanclaw, for the intellectual curiosity and thrist for knowledge, with a side of Griffindor for the heroic deeds 
As for why she was sent to the conclave, there are a few reasons. But that time, she's in his mid-twenties and has spent years isolating herself from the clan, although she loves them dearly. As a teen, she was bitter at the fact she'd shown no magic even though she is Keeper's daughter (Deshanna is her aunt, and the old keeper was Deshanna's older brother). Like most broody teens, she spent a lot of time on her own... brooding. She's gotten better as an adult, but she's still the scout sent forward while they travel, and when they are camping, it's not rare for her to spend days, and sometimes weeks away from the clan exploring ruins in search of lost knowledge (she has gotten a lot of the same instruction as a clan's first, so she's probably more educated than many of the other hunters. Her ideas about their history though tend to be controversial. but, that's what she's figured out from exploring ruins!)
So, Deshanna thinks it's probably a good idea for her to explore the world a bit, as she feels Ellana is getting stifled by clan life. She is also used to surviving on her own, is educated, can read and write, and she holds no contempt for the shems, so she makes a good candidate for it. Ellana isn't sure at first, but she lets herself be convinced it's a good thing. She's never set foot so far from her clan before though and the adventure ends up being more than she bargained for 