How long will it take me to lose 50 pounds (details inside)?

I'm 16, 5'5, female, and weigh (since the last time I was weighed which was probably 6-8 months ago) 170 pounds.

This summer was a little more active for me because I worked at a camp where walking long distances was the only transportation around and heavy lifting, bending, crouching, and carrying was part of the work.

A little less than a month ago, when I returned home, I decided I wanted to start seriously losing weight and keeping up with exercise and diet (though I had been buying healthier food, watching portions, etc. beforehand, but now more intensely. Whole grains, more fruits and veggies, little red meat, cutting out sodas (except for special outings) and sticking to water and tea (honey sweetened), soy milk (with calcium), and generally healthier ways of eating as well as portion control and eating small meals 5-6 times a day.

As far as exercise, I've been walking briskly 30-40 minutes a day, very occasionally doing yoga instead for 45 minutes, and as of today have worked out an exercise routine to keep up with during school, and it goes as follows:

Walking (with a jog around the track at the elementary school) 3 times a week for 30-45 minutes

Yoga on weekends

For the other 2 days, I've come up with a weight-lifting/muscle 'toning' regiment by looking around on Ediets, and this is what I came up with:

Squats with weights -30 reps
Lunges with weights - 15 on each leg
Hip raises -45 reps
The Bicycling-Elbows-Touch-Knees thing - until tired
Push-ups in Dog Pose - 45 or so
12-15 Barbell raises + 12-15 Tricep Extensions - starting out with one set, eventually building up to three with 45 second pauses inbetween.
12-15 Chest Presses

With all of this (being consistant with it!), how long should it take me to lose 50 pounds? 40? 35?

Thanks for your responses! ^^

Nice regimen! Sounds like you're getting serious and self aware, which is good to carry on later in your life! I seriously doubt that it will take more than eight months to lose fifty pounds on that regimen. However, remember that muscle weighs more than fat! So if you see yourself losing little weight, no need to despair! It is most likely you just developing more muscle, which is a great positive!

anything more than 2 pound a week is not healthy

most likely 5-6 months