If your job will allow jeans, then OK as long as not too tight too low cut. Leggings, no; nice casual skirts or dresses (flowered, other prints?) or not young enough? I have to say that a woman I knew (same age range) looked ridiculous in her "young" clothes - leather pants and skirts, Juicy sweat pants and jackets - her problem was not her figure but that she looked like a middle aged woman who did not realize that she was not 20. And although you don't mention it, I also do not think that yoga pants are proper except to class and to and from the house. Some people don't know that the pants with the flower on the rear end are yoga pants, and will wonder why anyone would wear pants with a flower on the rear.
Is it so casual that you can wear shorter pants like capri or long nice shorts? We saw some of the BCBG nice shorts on sale in the outlets - but you have to be very slim to fit into what is left (good for D, not me:()