If you looking for inexpensive ways to ship your souvenirs, and those extra packages from your girl's trip, use mail carriers such as Fed-Ex, UPS, or even USPS.
Here's the value.
1. Depending on weight, it is cheaper to ship your items than paying for an extra bag
2. Your items are insured and if they are damaged, it is less of a hassle to get reimburse from the mail carriers than the airlines.
3. Since you are shipping items directly to your location, you don't have to worry about lost bags and messing with claims from the Airline