The term toning up drives me nuts it muscle, fat or water and you can’t tone fat or water. The only way I know how to “tone” (I prefer shape, sculpt or build) muscle is with strength training in turn she will lose fat and water fluctuation is normal in everyone but she can manipulate sodium IE cut back on it to help reduce water weight prior to the trip.
As for specific workouts there is a lot listed in the reference stickies however it would be pretty simple to take your GF with you to the gym to do the same workout you do of course more than likely will be with lighter weights. There is no reason she can’t do the exact same exercise you do same rep range and sets as well. Also of course to see best fat lose results she will need to include cardio 3-4 times a week as well as a good balanced diet also listed in the stickies.
As always I recommend you GF sign up then we can get her specific stats as well as daily nutrition and give her more one to one guidance.