Different colors on different monitors?

Why do you assume that a particular shade of color, or it's brightness, will be the same on all monitors? If that were the case, the only difference between monitors would be refresh rate and size.

Printers, scanners, monitors, video cards and ambient lighting all effect color reproduction.

Well, I didn't really mean that the photo will look right on every single monitor, but how do I know that the image looks right on other monitors besides mine?

I'm tempted to ask which "other" monitors.. but let's not go there.

The only way to make sure that two mointors will reproduce colors/brightness/contrast equally is to calibrate both monitors (with their computers) in the same room, with the same ambient light, with the same calibration program.

No to worry though. If you carefully calibrate your monitor, then what you send to other people should look very close to the original, if their monitor is also calibrated.

The differences you are seeing (and posting photos of both would help) are usually due to faulty Gamma settings, on either computer, or both.

She probably had her contrast set to something very low...