Weight loss question (I'm 5'4"; 145lbs)?

If you were 5'4'' and 400 lbs, then 10 lbs per month would be fine. However, in your case that's a little much. Remember the human was never meant to do anything drastic. Also, you want to give you r skin time to catch up with your weight loss so let 10 lbs be the max you lose in a month