ahh this is 2.5 years old
My post was unclear, what I meant is while you can look and say, hmmm that is an old chicken, you cannot say, this is a 3 year old chicken, or a 5 year old chicken. There is no way to know for sure.
Added pictures..Post some pics and collectively, we can give you an idea....
added picturesDid the person you got them from refer to them as pullets? Are their combs red or pale pink? Examine the vent. Is it dry or moist? A moist vent means eggs are possible. Locate the two bony protrusions on either side of the vent. If you can fit two fingers between these, you can expect eggs soon.
I've noticed that hens, as they get older, tend to get wider "fender skirts", and these hang lower toward the ground. Young pullets and very young hens will have much more leg showing with "pantaloons" partway down the leg, since they haven't developed fender skirts yet.
The older the hen, the closer to the ground her body appears. But you really aren't going to be able to tell how old she is in years. Hens don't have tree rings you can count, unfortunately.