Hi, I only know a Tina Kalivas. If it's her you're talking about: all i know is that she's a young Australian designer and her pieces are often very geometric looking (well to me) but still practical. They usually have a lot of structure (like corsetry?) and often bold colours are contrasted (e.g. white and turquoise). She's got a strong enough style in Australia at least, for anyone to tell her designs apart imo.
I think she's getting quite popular (of course not as popular as Alice McCall, Kirilly? Johnson etc at the moment) and I think she's one of those designing for Target in Australia right now.
Sorry that isn't much.
If that wasn't her then sorry for being no help!