I just flew on two 19-hr flights with Meg, and it was a great experience. I used the
Bergan Comfort Carrier and it worked great. It was small enough that I could hold the carrier on my lap, and it has some handy outside pockets. There was some rogue stitching on teh bag (like a snarl of yarn!) which I was NOT pleased with, but it didn't affect teh quality of the bag.
Definitely bring blankets, a small water bowl, a couple treats, a toy, ***WIPES***, paper towels, doggie bags, and pee pads (I took Meg to the bathroom and let her go there). Line the carrier with a pee pad in case of any accidents (especially since your baby will be so young). Buy a bottle of water before you get on the plane so you don't need to worry about the flight attendants bringing water for your pup. And make sure you take her for a good walk before hand to tire her out. Also - given her age - try to get as much food as you can into her before you get her on the plane. She probably won't want to eat much on the plane, and then will be in a new home and might not want to eat at first, and you don't want to risk a case of hypoglycemia. Some people will tell you to not feed the dog before the flight, but better a poop on the plane than a hypoglycemic dog!! On that note, buy a tube of nutrical and ask your vet to print a prescription sticker for it so you can get it on the plane. I did this and it worked perfectly, but --- I was nervous so I also took an old pink Blistex tub, cleaned it, and filled it with nutrical.
Note: FAA regulations won't let you fly a puppy before they are 8 weeks old, and you will need a health certificate issued within 10 days of travel. If the puppy is of age (3 months, legally), it needs to have a Rabies shot given MORE THAN 30 DAYS before travel. Otherwise you could potentially have to deal with quarantine issues. Hopefully that wouldn't happen since you'd be staying in teh US, but each state has its own regulations.
Feel free to PM me if you have more questions!