Hroki can be found during the day at the market stalls just inside the gates. She works at the Silver-Blood Inn, which is owned by her parents, Frabbi and Kleppr.
Her schedule consists of spending all day at market and working the inn at nights. She thinks Hogni Red-Arm is the most "disgusting" merchant and may be found bickering with him. She shops at Kerah's jewelry stall and will tell her she's looking for something exotic that no other girl in Markarth has, as well as take interest in a ring made by Adara.
Hroki is the only adult in-game who has the Child class (This could possibly mean that she is a teenager).
Every time you try to talk to her after you drop a piece of armor and still say "Consider it yours," the only dialogue she will have is, "Excuse me, I'm assuming that armor you got rid of wasn't an accident, but just in case, I wanted to make sure I can take it."