The character of Jessica, when she is analysed carefully, reveals a number of different competing interpretations. On the one hand, it is possible to view her as a daughter who has suffered greatly because of her father and his miserly nature. She complains to Launcelot in Act II scene 3 for example that the house of her father "is hell" and she is sad that he will leave, as he offered the only light and happiness that she was able to experience. She is shut up and locked up just as carefully as her father's wealth, and it is clear that this would be difficult for her to cope with.
However, on the other hand, the text also reveals a very different kind of Jessica that is in many ways opposed to a character who engages the audience's sympathy. This is the Jessica that plots to steal her father's entire wealth and then goes on to spend it, if Tubal is to be believed, in a deliberately profligate way. In Act III scene 1, Tubal deliberately provokes Shylock by telling him of how his daughter is spending his wealth that he has worked so hard to accumulate:
One of them showed me a ring that he had of your daughter for a monkey.
This ring, being a gift from Shylock's wife to him when he was a bachelor, seems calculated deliberately to hurt and wound. This gives a very different impression of Jessica as a wanton individual whose stealing of her father's wealth and her deliberate marriage to a Christian is meant to wreak as much damage on her father as possible, which gives the audience a very different impression of her character.