Mary Ann Boyden's obituaries indicate the family traveled in the 1860 James D. Ross handcart company. The 1860 Ross company was not a handcart company, nor did any handcarts accompany it. The only handcart company that year was the Daniel Robinson company. However, the both the Ross and Robinson companies have complete rosters and the Boyden family is not listed on either. Further research is needed to identify the company with which the family traveled.
Her surname is "Lees" on the death certificate and Find A Grave website.