What are the Shakespeare allusions in I Don't Know How She Does It?

In I Don't Know How She Does It by Allison Pearson, the sonnets and romantic works of Shakespeare are often referenced and alluded to.
These allusions are most obviously seen in the sub-plot of Kate's romantic flirtations with the suave American businessman, Jack Abelhammer, who e-mails her Shakespearean sonnets as a method of flirtation. The two also have a discussion about a particular poem in which a man tells his lover than he wishes seven years could be experienced in a single night. Jack suggests the poem to be a work of Shakespeare, but Kate disagrees, attributing the work to Marlowe. Kate humorously writes,

"That's the unfair thing about Shakespeare, though—everything belongs to him whether he wrote it or not!"

Later, Kate also writes that the actor Carey Grant is a contender for the title of "Greatest Englishman with William Shakespeare." Clearly influenced by Shakespeare and other English Literary giants, I Don't Know How She Does It shows an appreciation for the Bard's endlessly rewarding poetry.