As we grow older, we lose muscle mass, and therefore don't burn calories as effectively. So yes, get your resistance/weight-lifting done. This increases strength. Working on your core and Pilates will help with balance and flexibility. If you are looking to burn calories and lose weight, "Cardio is King!" Spinning, running, walking, swimming 2x/week is excellent in addition to these other things.
Have you heard of Tabata training? I can teach it to you: it's 25 minutes of intervals (cycling, running, walking, swimming or any variation of bootcamp-style moves) and boosts your metabolism for the rest of the day!
Sometimes, "Life gets in the way," of course. We all have responsibilities and time is important. If you are looking to coordinate all of these ideas into one hour, call me for a private session... to "Keep the Peace" with you and your body!