There is ZERO possibility that she would have been allowed in a store with potentially armed citizens. Each of the "customers" would have had to be screened, if they were customers at all. I suspect three things: First, the "customers" were secret service or otherwise employees of the WH; second, that Target likely contributes heavily to the DNC in order to get this "plug", and third, the specticle of very expensive vacations and very expensive jewelry and the general exeberance of this family does not poll well, hence the "I'm an everyday American" photo op.
I'm going with this
The store manager said they didn't get any warning and almost missed the fact she was there.
And there is no possible way he was fibbing. People never do that, especially when it concerns the POTUS and security.