First some background for those not up on English conscientious fashion designer Stella McCartney (who happens to be the daughter of Paul and Linda):

In 2003, Stella McCartney launched her first perfume STELLA. In addition to the main line collection, a long-term partnership with adidas was introduced in September 2004. The critically acclaimed sports performance collection adidas by Stella McCartney, has since successfully grown to include several athletic disciplines including running, gym, yoga, tennis, swimming, winter sports and cycling.
In 2008, a new lingerie collection of aspirational styles that reflect a modern woman’s needs was launched. In Winter 2010 Stella McCartney introduced the Falabella handbag, distinguish by a braided chain detail the bag has since become one of the designer’s best-selling items. Also in 2010 the first Stella McCartney Kids collection debuted, capturing the spirit and energy of kids today for boys, girls and babies ages newborn to 14 years. Since 2011, all sunglasses complimenting Stella McCartney’s collections are eco-friendly; which has since also expanded into the optical range.

And now the news, revealed by Stella yesterday via a series of three tweets: