Charles Burney wrote of her singing that "by a natural pathos, and perfect conception of the words, she often penetrated the heart, when others, with infinitely greater voice and skill, could only reach the ear."

On 13 March 1732, she made her professional debut in the title role of John Frederick Lampe's setting of Henry Carey's Amelia to positive reviews, at the Little Theatre.

The marriage proved beneficial to Susannah's career and position in the London theatre, as she became a regular at that house for many years, now performing under the name "Mrs Cibber".

Susannah received hours of acting tuition from her new father-in-law, and he helped teach her valuable vocal intonations and tragic gestures that shaped her into the most celebrated tragedienne of her time.

Public audiences began to view her as the young ingénue of the Cibber acting dynasty, which in turn, helped land her leading roles.

Her brother Thomas also benefited from the marriage as he became house composer at Drury Lane, and wrote music for a number of plays and pantomimes over the next several years.

The following year, Cibber portrayed the role of David in the original production of Handel's oratorio Saul and she appeared in the world premiere of her brother's immensely popular masque Comus.

[5] The resultant relationship between these three people led to a notorious lawsuit in 1738, in which Cibber accused Sloper of "Assaulting, Ravishing and Carnally Knowing" his wife.

One account states that Cibber forced his wife at gunpoint to sleep with Sloper; another places a spy in a closet at the scene of one of their trysts, in order to gather testimony for the lawsuit.

She moved to Dublin, and in the autumn of 1741 for a busy season at the Aungier Street Theatre with her good friend and mentor, the actor James Quinn.

Legend has it that Dr Patrick Delany, the chancellor of Christ Church Cathedral, upon hearing her sing "He was despised", proclaimed "Woman, for this be all thy sins forgiven thee!"

No person of sensibility, who has had the good fortune to hear Mrs Cibber sing the oratorio of the Messiah, will find it very difficult to give credit to accounts of the most wonderful effects produced from so powerful a union."

Burney, referring to these evenings, wrote that he found himself "in a constellation of wits, poets, actors, and men of letters", including Handel, Garrick, and Arne.

[9] Her roles included Jael in Deborah, Lichas in Hercules and David in Saul, and she sang in the oratorios L'Allegro, Alexander's Feast and Messiah.

In 1744, Cibber became David Garrick's leading lady at Drury Lane, the theatre managed by her father-in-law, and their partnership and friendship (reflected in letters) continued until her death.

The boy's mother, Cecilia Arne, suffered from recurring health problems and this, compounded with Thomas's busy work schedule, made it impossible for his parents to care for him.

The poet George Keate wrote in that year "A Poem to the Memory of the Celebrated Mrs Cibber":[13] ... Closed are those eyes which knew each varied art, And could my meaning with such force inspire; Call tears of pity from the melting heart, Freeze with wild horror, or with rapture fire!