Why is the woman thinking of postponing her trip?

M: Will you be making the trip out to Los Angeles next Monday?
W: I was planning to, but something has come up,(59)so I was contemplating whether or not I should delay my trip to the week after. Why do you ask?
M. My brother who moved to France five years ago is coming to LA next week on a business trip, so I was thinking of going out there to see him.(60)And since I heard you are going, I thought maybe we could drive down together.
W: That sounds like a good idea. I do have to make a trip there, and it would be nice to have some company. Hmm...tell you what, I will see what I can do to take the trip next week after all.(61)Let me give you a shout with the details after lunch today.