Christie Brinkley has been showing off her gardening skills as she tended to some flowers in her greenhouse – and the structure could belong in a botanical garden.MORE: Christie Brinkley mourns sad death of co-star with heartfelt tributeIn a series of snaps, the supermodel beamed as she tended to some beautiful red flowers, while a host of other plants filled the building.And if fans looked up, they could see that the greenhouse's roof stretched to almost half of the height of Christie's