Adjustment of Status - I-485

My PD is May 03, 2016 and I had my interview yesterday. First, the officer asked us if there is any document we would like to show to her. I give her the common bank information, common car insurance, common health insurance, documents shows that me and my husband being the beneficial of the retirement plan for each other.
And then she started the interview. The interview is pretty easy. The officer asked my husband the basic information about himself, e.g. name, DOB, ssn and so on. And then she asked me my information (e.g. DOB, SSN, my parent's first names). And then the officer asked all the NO questions on the I 485 to me. After this, she said we need to remove the condition after 1year and 9 month. And give us a form to sign. She said our case should be approvable, but she need to check if they need more information. And said the green card normally takes two weeks to arrive.

And today, the online status of my I130 changed to "Case was approved". But my I485 is still "Interview was scheduled". Does someone knows how long it takes to get my I485 approve? Why she cannot approve our case in the spot? Thanks.