How will the wild bird eggs hatch?

So, this morning, my mom and dad went fishing, and so my mom brought home a nest with 4 little eggs in it. It is very small, and has like black stripes on some of it and is kind of blueish color. So I told my mom where did you get it, and she said I saw it from a little branch, and it was going to fall, and so thats why my mom brought it back with her. Also, my mom said that there was nothing by it and it was just right on the branch. So, my possabilities are that, the bird mom could of left it, or the temperture was to cold and maybe it wouldn't survive. Right now, I am trying to warm the eggs, and so please tell me if it is most likely dead or alive. P.S- It wasn't on the ground. Heres a picture of what the eggs kind of looked like:http://us.cdn3.123rf.com/168nwm/inspiration22/inspiration220906/inspiration22090600018/5077205-four-small-baby-blue-eggs-snuggled-into-a-deep-nest.jpg