Yes, hens can grow spurs. Generally it is the older hens that this happens too. All chickens, rooster and hen alike have the gene to grow spurs. But in hens this gene is turned off. But as the hen ages, sometimes this gene can get corrupt and cause her to grow spurs.
If you do indeed think she has a spur that is growing improperly, you might take a look at this thread on removing a spur....http://www.backyardchickens.com/t/37548/removing-trimming-rooster-spurs
See if you can get someone to help you upload a pic so we can all see if this is a spur or not. :-)
Thank you 2 crows. when they said spurs, I was thinking John Wayne :) So lady chickens can get spurs, I didn't know that. Right, I will tackle this problem now I know what it is.
I don't have a fancy mobile that takes pictures but I do have a digital camera and maybe that will do the job, trouble is finding the manual, its not where it should be, someone has moved it. I can see it would be useful so I will edge toward doing this. Thanks two crows, love the name by the way.