You are spot on, Myra. No one -- man or woman, of any age, on any routine, will build muscle at the same rate they lose fat. One weird thing I've noticed about muscle mass --for myself, anyway -- is that once you've built some, it is relatively easy to maintain. I say this because I stopped working out with my trainer just about a year ago and stopped following a heavy lifting schedule because once I started my job, I couldn't get to the gym in the mornings, and I need to exercise in the A.M. as opposed to evenings to do my best. So for the past 12 months, I've been lifting, still, but not nearly as often, not nearly as much weight due to only using at-home equipment, and not following any sort of plan like I used to. Yet in that time, I have retained virtually the same body composition (I did have my trainer do a caliper body fat measurement and I'm still 16.7 % -- was 16.4% a year ago) and I'm the same weight (144-146 lbs depending on the day, and I weigh at least 4-5x/week) and I don't feel I've lost any measurable strength or stamina. So the old "use it or lose it" motto is somewhat true but for me personally it seems I can maintain my level of fitness even with a different, less strenuous exercise regimen.
Norma is still following my blog and "coaching and encouraging" me. This was her email today after reading my post that said that we lose fat a lot faster than we gain muscle. I am glad to be able to look forward to an easier time maintaining my muscle mass once I achieve it. It's news we all can use.