I saw a lot of posts about cath back on the 2nd page
She's not too
difficult to get especially if you plan on getting Viki later, since his parts drop in the same area and they will take you much longer. The mansion is one of my favorite leveling spots because you can rush through a room and have a trail of monsters happily following you to their death. Drop rate also seems to depend on level I have gotten 4 hip drops in the k2 servers, and only one of those was gotten by a player over lv56.
So, if you plan to get her just grab a character that can aoe and one who can tank then go nuts mobbing. There's a list for the drop rates here
she's definitely worth getting if you active level.