Directly from the paypal site
PayPal offers a free, convenient and easy way to take care of your shipping needs with a variety of helpful shipping tools - with no hidden fees.
However, I could not find the fees.
As far as SmithCart goes, their job is done with the order and payment collection. Although we can imagine further integration with UPS and USPS, Canada Post and Royal Mail Group, I suspect that eBay/PayPal have far more resources, volume and power to accomplish this task. I do know that Canada Post shipping labels are only available through their own software or exclusively through PayPal and UPS only allows daily pickup customers to use OnLine Compatible applications like WorldShip and ShipRush Pro Edition.
Personally. I would use the individual shipping sites - but there's the hook with PayPal - how do you get the information back into the shipping sites?
All said and done, this works mostly with single orders of one carton. I have no clue how multiple tracking numbers are handled.
Helpful page
http://www.newlifeauctions.com/shippi...
To be honest, I had to reread your question and still have not determined if she spends too much time or money or is just looking for an alternative or automated method.
This looks promising
http://www.zfirm.com
http://www.shiprush.com/downloads/ass...
http://www.shiprush.com/products/asse...
I do have a few suggestions for a client side solution, but it depends on too many unknown factors at this time.