I am 5ƈ'' and weight 160lbs. I have had a child and I'm still carrying the baby weight (he's not quite 2 yet). I've been doing 30 min of cardio 5-6 times a week along with basic strengthening and conditioning exercise. I'm working up to about an hour of cardio as my goal, as well as a few other fitness goals.
I wear the weight well I think, I don't look like I weigh 160. My measurements are 38-33-42. How much weight do you think I would have to lose to get to 34 to 36 inch chest size, 24 to 27 inch waist, and 34 to 38 inch hips.

I am 5Ǝ" and weigh 110 lbs. My measurements are 32B bust, 23 in waist, and 33 in hips. I am underweight according to a weight chart, but I am very slight build in bone structure, so I look thin but not gross skinny. According to a weight chart at 5ƈ" you shoud weigh 110 lbs, but if you are bigger boned you may be able to carry 10 more lbs. I would say you would need to lose 40 lbs.

Google Body Mass Index and It'll give you sites where you can enter all that info and it will give you suggested weight and tips on getting there.

You're thinking idealistically. The amount you want your bust to go down is not proportional to what you want to lose on your stomach and hips.