HI Mary
Did you check over at the Chi Marathon forum? I realize you probably have a week left before the next half marathon, right? So treat it as a taper week, following the same mileage plan you did for your last one.
As for your cadence, 175 is good if that is where you are comfortable for now. But over the next few months/year, try inching toward 180 for more efficiency. You can set your metronome for 180 and hold that cadence for as long as you can stand it (could be as short as 100 yds). The next time you run, push the distance a little further. Over time your body will adapt to and relax into the 180 cadence.
Keep us posted.
Laura Houston
Certified Chi Running and Chi Walking Instructor
Seattle WA