If you love your pet, like we all love ours, please leave her home with someone who will care for her and love her. She will suffer no separation anxiety after a day or so. You may be exposing her to much more potential suffering if you take her on long flights, foreign atmosphere, insects, molds,, and so on. Have you discussed this with a licensed veteranian? I, for one, would not wish to be exposed to any dog in the airline cabin (you can't possible put her in baggage compartment). People have allergies and the issue of tolerating a dog whining or making unhappy sounds or barking during a 10-15 hours flight is cruel to the other 200+ passengers.
I am the wife of a 20 yr senior commercial airline pilot and I can tell you no matter how cute a pet is, it is a detriment to every passenger on the plane.
Be kind and see how happy you [all] are when you return home to your safely kept chihuahua. Tell her stories of your trip.
Have a wonderful new life--hope all goes well for your wedding and honeymoon.