I wish giving it your all was enough, but most of the time its not. Work your self up to being able to do about 50 pushups in two minutes, 65-70 situps in two minutes and be able to run at least three miles without stopping.
The basic Army PT test is pushups, situps and a two mile run. Its not hard once you start training for those events. Keep doing pushups, a lot of pushups, until you can't do them any more, your number will go up. Its sounds like a horrible form of PT, but trust me, it works for some reason. The running will just come with time, especially if your not used to running. If running a straight mile is hard for you, mix it up a little, do some 100 yard and 50 yard sprints with a rest period or jog in between. The situps are the the same way, just do them, do a lot of them, often. Your abs are able to recover rather quickly, as opposed to other muscles in your body, so you can work them 4 or 5 times a week. I would recommend running 4 to 5 times a week, at least a mile, to get your body used to running. It if you can't run the whole way, walk some of it, or slow jog. Eventually your body will get used to it and adapt.
At boot camp, if you give it your all, your going to pass, thats the way it goes. Boot camp is not set up to make you fail, especially army boot camp. Not to be rude, but I've seen some hefty females make it through Army boot camp alright.
Hope this helps, your on the right track, just get there and PT.