Welcome to the board Shoefly. I will give you the current info but double check prior to day of travel as with TSA and Nonrevs policies change.

Recently the standby baggage policy on US Airways was changed. Now if the bag has a standby tag it goes on the flight unless there is a weight and balance problem. Therefore your bag now may get there before you do.

If you are going to be flexible in you destination, which you still are allowed to be as your Sister's Registered Companion, you may wish to dump liquids and gels from your carryon and go to a Walmart (since most are 24 hours) or drug store to pick up some small replacements when you get to your destination.

Don't let the new TSA rules stop you from enjoying the travel benifit your Sister has given you.