The correct answer to this open question is the following.
You did not mention the novel or the play you are referring to.
However, doing some research we can say you are referring to the play "The Merchant of Venice," written by English author William Shakespeare.
If that is teh case, then we can comment on the following.
The obstacles and the possible outcomes of Portia and Nerissa's plan are that they have to disguise themselves and need to travel to a monastery "2 miles off." Another obstacle is that Lorenzo could deny this petition and opposed the Portias' decision. In the end, Lorenzo accepts to support Portia and Nerissa.
The outcome of the plan could be that they were recognized although they would be disguised as young men when they follow Graciano and Bassanio to the city of Venice. However, both ladies are so sure that their plan is going to work out just fine, to the degree that they bet on who will be more convincingly acting the role of a man.
