That is a 2012 model year Jimson weed. Here is what it looked like last fall http://en.wikipedia.org/wiki/File:Bielu%C5%84_dzi%C4%99dzierzawa_Datura_stramonium_Seed_01.jpg

It looks like Datura stramonium… Jimpsonweed. I was always a fan of jimpsonweed, those pretty white flowers with the purple throats… Datura stramonium is an annual, but once you allow it to set seed, you won’t have to plant it again… Jimpsonweed is a nectar source for the tomato moth (manduca sexta) and the button weed moth (xylophanes tersa) aka tersa sphinx. So… you might want to watch those blooms at dusk… Also plant 4 0’clocks for those moths… similar flowers that open at the same time… attract the same moths… very exciting…

That looks like Jimson Weed (Datura stramonium http://www.photosbotanical.com/img19980.htm ) that has died off over the winter. Don’t worry, though, as from the number of seedpods it has there should be plenty more coming up soon, which may not what your sister wants.