[5] Scholars such as Paul Wesley Chilcote consider Crosby to be the busiest female Methodist preacher, as she preached up until the day she died.
[16] In the winter of 1749, Crosby heard both George Whitefield and John Wesley, the founders of Methodism, preach in London.
[6][24] During the summer of 1758 Crosby moved to the Moorfields, to live with Bosanquet, Sarah Ryan, and Mary Clark, all of whom would become prominent female figures in Methodism.
[27] The women at The Cedars helped to care for 35 children and 34 adults, most of whom were dirty, unclothed, ill, and/or uneducated.
[28] Education at The Cedars included instruction in manners, reading, religion, writing, nursing, and domestic skills in order to prepare the children for life beyond the orphanage.
[31] The women asked Wesley to send them a preacher in order to have a more religious environment inside of the orphanage.
[32] Despite this, Bosanquet and Crosby continued to hold their own religious services on Thursday nights and began to attract large crowds.
[34][18][35] The move was made from The Cedars to Cross Hall in order to decrease costs (since the women would be able to grow their own food), to give a better environment for the children, and hopefully improve Ryan's failing health.
[36] However, Bosanquet and the other women had little to no experience with farm life, and growing their own food did not prove to be as successful as they had hoped.
[38] Bosanquet, who had controlled most of the operations of Cross Hall, closed the orphanage on 2 January 1782 following her marriage to John Fletcher.
[42][1][6][43] Usually, in a class setting, Crosby would have given individualized advice to a small group of less than 50; however, since there was such a large crowd, she could not do so and decided to preach instead.
[44] Her preaching consisted of reading a hymn, praying, and telling a story of how God had impacted her life.
[47] According to many scholars, this marked the beginning of Wesley's acceptance of women preachers in Methodism, and made Crosby the first woman to receive this title.
[50] In 1769, Wesley wrote to Crosby, permitting her to give pieces of spiritual advice, or exhortations, in her preaching.
[51][52][53] Some Methodist male leaders opposed this practice, but Crosby and Bosanquet continued until Cross Hall's closure.
[27] This was the direct result of a letter written by Bosanquet to Wesley, defending hers and Crosby's preaching at Cross Hall.
[55] Bosanquet argued that women should be allowed to preach in Methodism when they experienced an 'extraordinary call,' or permission, from God.
[69][70] She was buried in a shared grave at Leeds Parish Churchyard with her colleagues Sarah Ryan, and later, Ann Tripp.