Most probably the last British monarch to be suckled by a wet nurse was George VI, the father of Elizabeth II. "Queen Victoria did not breastfeed any of her children, and evidence exists that wet nursing continued through Queen Victoria's reign and beyond (Rosen, 2008, para. 11), so Mary of Teck would have most probably employed wet nurses as well. However, "by 1900, the once highly organized wet-nursing profession was extinct" (Stevens, 2009, para. 16). Technology had simply put the wet nurse out of business: By 1912, rubber nipples were easy to clean, and cow's milk could be stored safely in an icebox (Stevens, 2009, para. 28). Thus, the Duchess of York, the former Lady Elizabeth Bowes Lyon, would not have needed to employ a wet nurse--nor could she necessarily find one by 1926--if she was unwilling or unable to breast feed her daughter herself. Elizabeth II had a nursery nanny and a nursemaid looked after her (Smith, 2012, pp.13-14). Both of these individuals could have fed Princess Elizabeth without employing a wet nurse. It wasn't until much later that medical science discovered that human breast milk furnished certain benefits that bottle feeding didn't give children.
Rosen, B. (2008, August 11). Wet-nursing in Victorian England. Victorian History. Retrieved from http://vichist.blogspot.com/2008/08/wet-...
Smith, S. B. (2012). Elizabeth the Queen. Random House, pp.14-15. Retrieved from Amazon.com
Stevens, Emily E., Portrick, T. E., & Rickler A. (2009). A history of infant feeding. Journal of Perinatal Education. 18(2)L 32-39. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles...