Thank you all for your replies! My apologies - I should have mentioned in my original post that the tickets were $273.50 per person; as much as I'd like to cancel and find a lower-priced, more convenient alternative, I'm not sure that's an option

Unfortunately, our dates are pretty well set in stone (as I'm also flying my sister out to the islands from her home in CA as a surprise, so that the ENTIRE family can be together), so leaving a day later and utilizing the HNL-EWR flight won't work.

At this point, I'm inclined to just accept the change rather than mess around with switching airports, etc. I fear (though this is perhaps irrational) that, by switching one ticket to BWI or DCA and keeping the other two as a PHL departure, that things may get screwed up.

Thanks again for your comments, they are most appreciated!