The relationship between Portia and her father is an interesting relationship to consider in this play. This is because Portia's father died before the beginning of the play, and she is left to carry out her father's particular instructions regarding whom she should marry and how her future husband will be selected. This is something that she finds very difficult to cope with, as she explains to Nerissa in Act I scene 2 when she talks of how "the will of a living daughter [is] curb'd by the will of a dead father." She is neither able to choose nor to refuse, and she finds this very unjust. However, Nerissa reasons with her and tries to help her see that her father was acting in her best interests:
...the lott'ry that he hath devis'd in these three chests of gold, silver, and lead, whereof who chooses his meaning chooses you, will no doubt never be chosen by any rightly but one who you shall rightly love.
Nerissa perhaps sees what her mistress is unable to see; that Portia, as a wealthy heiress, will be courted by all sorts of men, both suitable and unsuitable. The test her father devised, out of love for her daughter, will therefore ensure that the person who succeeds in guessing the correct casket will be of a suitable character to marry Portia. This relationship offers an interesting comparison to the relationship between Shylock and Jessica. Portia feels constrained by her relationship with her father, even though it is for her benefit. Arguably, the sense of entrapment Jessica feels is something that is negative, and she elopes to escape her father.