It's usually advised to go with a solid color suit in a traditional color (black, brown, navy blue, or grey.) Houndstooth is a little loud and borders that fine line between formal/informal. You definitely have a little more room for variance as a female (as opposed to males who would never be able to pull off anything but a traditional suit in this situation,) but an older, more conservative interviewer might think it's too loud and somewhat unprofessional. It'd be a gamble in my opinion.
Have you tried looking at a Banana Republic store? They have a full line of petite clothing now that goes down to XXS or XXXS (I can't remember which for sure--I stopped working there back in June.) A tailor then could make it a perfect fit most likely, and their clothing is very professional in both appearance and quality (I bought my interview suit there.)