Adjustment of Status for people in K status can take around a year or so.But you have no basis for worrying. As long as you entered the US on K-2 visa before you turned 21 and while unmarried, and your K-1 parent married within 90 days of entry, you qualify to apply for Adjustment of Status, at any time, with no age limitations. That means you qualify for Adjustment of Status even if you turn 21 before you apply for Adjustment of Status or before it is approved.