"Toning" is breaking down and building more muscle while you exercise. To be "toned" is having muscle definition. Now, a woman does not bulk like a guy....not enough testosterone and genetics. However, a woman DOES build muscle while exercising...just the ad guys figure you use "Muscle building" and it will scare off women from trying. So many bad female myths to overcome. One of the biggest is "There aint no such thang as Spot Reducing"!
What you are really asking is if you can lose bodyfat while exercising and get defined muscles and eating proper nutrition. Yes, you can.
Your body takes fat from all over to fuel itself to lift or do cardio or whatever exercise you are doing. Where fat was stored first is usually the last to go (ie. Stomach) All it takes is time, patience, determination and stay motivated.
Eat 5-6 smaller meals a day as this will up your metabolism to burn the bodyfat/give you energy while building muscle. If you are eating pretty decently now, it is a matter of moderating your diet. Up the protein intake, lower carbs by cutting out overly processed ones and eat more complex ones instead (ie: whole grains/veggies). Cut Sugar and drink plenty of water. Use good fats.
Resistance workouts (ie. lifting for strength) is a good way to make the muscles work harder to burn the fat and increases your metabolism. A three day split lifting moderately heavy weights (machines and/or freeweights) using 4 sets of 10-12 reps
will do this. Rest a minute between sets. Warmup and stretch first. You can include some cardio right after the lifting or on your non lifting days.
I lost 60pounds from doing this through a college Women's Strength class for a year. Relearned how to eat properly and what to eat as well. Started in Fall 2002 at 50 years old at 5'6"/largeboned. Was this weight and more for 33 years of marriage, had two kids by c section and my body was a mess. Decided to do something about it.
After a year, I am able to get into pre marriage clothes sizes although weigh just abit more on the scales than back then. Muscle is denser. A tangerine size portion of muscle weighs about the same as two grapefruit size portions of bodyfat. So "losing weight" can be abit of a misnomer. However......I can live with the numbers knowing where it is coming from.
I have some osteo in my lower back and found the lifting has strengthened the muscles there. No more pain while sleeping on my back and walking is no longer a chore. Regained flexibility and able to move around better overall. Lifting will increase bone density....a plus if you are post menopausal as I am.... and help keep the body producing it's own HGH. I see too many women my age/older hobbling around with age related injuries. There were women in my classes who were taking it as a therapy for a variety of reasons. Gastric bypass, arthritis, and just wanting to keep healthy.
So whatever you do...now is the time. If you are younger than I am (52) you do have some advantages. If you are as old or older.....there is not better reason than some I just gave. Good luck on your choices.