Mtn Dew-
congrats on having such motivated daughters. My two kids (now 12 & 15) pretty much did the same thing for me, and you can do it.
After driving a desk, smoking, drinking (scotch), working too much, being over 200lbs, a couple of friends and my kids got me back into the fresh air 6 years ago. Moderated my diet, cut WAY back on smoking/drinking, and got active again. Now back to HS weight/pants size, done Rainier, Hood and quite a few other mtns. Hiked 15 miles out of the North Cascades on Sat, carrying 60+ lbs.
Remember, progress can often seem pretty slow, but it is well worth it!