Yes, I agree that you might be a bit overweight for your age and height, but you have to keep in mind that your body isn't fully developed yet, either, so you may grow taller, which could make your weight okay.
How long do you spend doing your cardio? When you walk your dog around the neighborhood, do you go at a nice brisk pace? I find that when I walk my dog, she wants to stop and sniff too many things, go to the bathroom a dozen times,etc, so I can't keep up my pace. I'm not telling you not to walk your dog -- just try to make sure you go at a really good clip; that's best for both, you and the dog.
I'm sure your mom fixes good healthy meals, so make sure you watch your portion sizes.
I do cardio for about 45 minutes, 3 days a week. And my doctor told me that since I started my growth spurt at a young age, I won't grow that much anymore. And I also do walk my dog at a nice brisk pace. My dog doesn't really stop to use the bathroom that much. So she just walks along with me.
Keep in mind that you are still developing and despite what your doctor says you can still grow. A female does not stop growing until age 19. You have a good five years to increase your height. I started my growth spurt at a young age too and I was 4' 10" at age 14. I was also told by my doctor that I would not grow anymore. By age 20 I was 5' 3". I proved him wrong. Everybody's body is different. But you can train it to be healthy which will help your body to function at an optimal rate. Don't stress too much on your weight loss because the added stress will not allow your body to burn fat properly. Take it all in stride don't get discouraged if you don't see changes on the scale right away. You have to think more long term instead of just a few short weeks. Its good that you walk your dog for at a brisk pace and cardio. My question is what type of cardio are you doing? Since you are young it will be easier for you to burn fat try doing dance based cardio like Zumba for example. Danced based cardio makes you work all your major muscles groups at the same time. You also need to start doing resistance training. Resistance training will help you gain muscles which in turn will increase your metabolic rate which will cause you to lose fat. Now you don't have to lift weights. Alot of people think that resistance training = using dumbells but it doesn't. Resistance training is any exercise in which your mucles have to work against an opposing force (i.e pushing, pulling, squeezing etc..) Since you are young I would recommend ballet type toning exercise for resistance training. I recommend the Lotte Berk Method these exercise tone and streamline and condition your muscles; improve posture; and will aid in helping you grow a few more inches. You can search for it on Amazon or Ebay. Here is the link on amazon.com:
For dance based cardio I would recommend Zumba, Ballerobica, Tracy Anderson Method or Shape Cardio Workout. Yo don't have to do all just chose one or two (so that you can alternate and don't get bored) that will work for you.
Here the links for the DVDs on amazon.com
If you are having trouble with choosing the right foods to eat try reading a weight loss book for teenagers. Nutrition is just as important as exercise for weight loss. You do not have to do anything drastic to your diet. Just make a few smart healthy changes to the foods you eat. I recommend The Diet for Teenagers Only by Barbara Schroeder. She offers healthy tips which are not too drastic and there is a food journal to track what you eat. Here's the link on amazon,com
Keep in mind that you should talk these programs over with your doctor if you choose to use them. If you are still struggling with weight and you see no changes in two or three months then you should have your doctor run a few tests to see if there is a underlying medical condition preventing you from losing weight and also go see a nutritionist that specializes with teenage weight management to help get you on the right track.
Best of luck and if you have any questions please feel free to ask!