Agree with angus9259. Unfortunately we've had our share of hardware (all cows/bulls/retained heifers now have magnets). Things to look for are swollen brisket, loss of condition, sometimes they drool, laying down on an incline with their chest elevated, stretching their neck, swollen legs, a dry hacking cough, she may start to lag or separate from the herd, temp is generally normal. Your vet can tell a lot with a stethoscope & you may want to give her a magnet. That said, I think she looks pretty good.