Maybe it just has to do with the artist portrayal of Rashta, but to me her social ineptitude and childishness seem genuine on her part. That woman is either not all there or one hell of an actress.
I don't want to spoil your reading experience, but since you gave me the go, i'll give you a couple hints:
-She's a former slave from a noble house.
-As an indentured slave, you are made aware of your place and society's rules, so that you never cross the line. Nobles have their pride despite their depravity, dirty laundry is never aired out. (so can she truly claim to be COMPLETELY oblivious?)
Footjobs are certainly not my thing, but reversible couple? yes pleaseლ(´ڡ`ლ)