Well yeah, that is a real possibility. But you probably won't ever know it if she does. The same way you have no idea what might be in her purse now.
Concealed Carry means just that, "concealed". In a pocket holster, in a purse or under a jacket you'll never know who might be carrying a firearm. The new Illinois law allows for "Partial Concealment", in other words if somebody reaches on the top shelf for one of those huge plastic bags with 96 toilet paper rolls and you see the bottom edge of a holster, that's OK. But open carry, ala Wyatt Earp, is not legal and brandishing, e.g. removing the gun from the holster or pocket to display it or intimidate anyone by waving it at another driver is also illegal and clear grounds to not only lose your carry permit but face serious felony criminal prosecution.
Finally, all private businesses have the option of posting their business as a "No Carry" zone with signs at the entry way. The signs must be clearly visible on entry.
A Cautionary Tale: When Ohio first passed it's concealed carry law, about 6 years ago, most stores put up "No Carry Allowed" signs right away, fearing shoot outs over parking spaces and the last box of Hamburger Helper. Gun owners started leaving business cards in those stores that said; "I'm a law abiding gun owner and I respect you choice, now I'm taking my business and money to your competitor that trusts me and the law and will let all my fellow gun owners know you don't trust us." More than a few businesses saw sales number drop a little. Over a year almost all the business gun ban signs in Ohio disappeared and no rash of shooting has broken out in Ohio or anywhere else the law allows CCW.
But I'm not sure how the signs will stop any criminal with a gun who might be planning on robbing a store?
