Unusual Visitor - Orange-Barred Sulphur Butterfly

It took a little searching to figure out what this little girl was. I say girl because the males are more orange, thus the name.
I don't know why she came up this far north. Usually they stay in the south, only occasionally visiting south Texas. More often you can find them in Brazil or possibly south Florida. I guess she was atracted by the turk's cap she was feeding on.
Unfortunately I didn't have the pleasure of taking this picture but my wife did along with several other pictures of the yard and gardens.