Erm.. you can't "tone" your tummy by running. You actually are just needing to lose the fat that's covering your abs.
For ultimate results losing fat, do
High Intensity Interval Training (HIIT) cardio. This means every time you hit that elliptical or treadmill, SPRINT AS FAST AS YOU CAN for 60 seconds, then jog for 40, then SPRINT for 60 and keep doing this. You should be pouring sweat and feel like you're gonna die.

Lift weights on the days you don't do cardio. Building muscle helps to burn more calories when you are rested. Personally, I don't like cardio but from lifting with a very specific workout, I've lost a lot of body fat in the past 2 months.
Also, 96lbs. is a little low... how tall are you? You sound like you might have a case of "skinnyfat" where your weight is fine, but you still look flabby. Lifting weights will help that, too.
Hope this info helps.