During the formative years, she had a dream to become a famous model. At the age of 16, the spokesman of one of the best modelling agencies in London“Select Model Management” noticed Donaldson. Soon, she became the leading model in fashion shows for such various designers as Chanel, Louis Vuitton, Moschino, Missoni and Jill Sander.

Lili also presented many fashion houses including“Burberry”, “Gucci”, “Versace”, “Fendi”, “Lanvin”, “Calvin Klein”, “Dior”, “Jil Sander”, “Dolce & Gabbana”, “Balenciaga”, “Roberto Cavalli”, “Hugo Boss”, “Alexander McQueen”, “Max Mara”, “Shiatzy Chen”, “H&M”, “Topshop”, “Aldo”, “Kenzo”, “Anna Sui” and “Gap”. When she was twenty years old, she appeared on the cover of American “Vogue”together with such popular models as Doutzen Kroes, Caroline Trentini, Raquel Zimmermann, Sasha Pivovarova, Agyness Deyn, Coco Rocha, Hilary Rhoda, Chanel Iman, and so on.

In 2007, Lili got a name of "Head Girl", as one of the mostsucceeded models all over the world. Besides, she was seen on more than 25 international covers of Vogue like the British, American, Italia, China, Australia, Japan, Turkey, Taiwan, Korea, Portugal, Spain and Russian editions. Three years later, she participated in Victoria's Secret Fashion Show. After this debut, for the next six years, she had been the regular participant of this show. Moreover, Donaldson is considered to be one of the top 30 models of the 2000s.

She also cooperatedwith the new Monsoon Accessorize campaign for Spring Summer 2011. There was some life-changing horse-riding accident in Lili’s life,after which she was unable to walk for three months. It helped her to realize that she had a brush with death, so she is enjoyingherself now. Donaldson is very enthusiastic and hardworking person. Due to the persistent work, her net worth is estimated to be nearly 5 million dollars.

As to the personal life in her biography, she has not been married. She does not have a husband or children. For some time, she was dating with American swimmer Michael Phelps. She was also involved in the relationship with French art director Vladimir Restoin Roitfeld.

Since 2013, her boyfriend is a French artist Cyprien Gaillard. It is also important to say that Lili is an active user of social media. She has her accounts on such popular websites as Instagram, Facebook and Tumblr. There are thousands of fans and followers on her pages. It is always interesting to read about her thoughts and ideas. Currently, Donaldson lives in London, England.