When should I put the description into my book?

In my opinion you should add her description into the story itself like when you said," whipped her long hair around" you should describer the color the texture (wavy, curly, straight, etc.) and describe her clothes or something by saying the elevator was really hot so she started to shed her layers of clothing describing each one. If you want to describe her face talk about how she looks at herself in the mirror in the elevator examining her face saying something like," My face felt so out of place in this frigid city I belonged in California." Your story so far is REALLY GOOD! I hope I helped?