Advice on running two wallets please
You don't need to be running two wallets at the same time. Funds can be received while offline. Do the following:


Create a backup of your current wallet.
While Bitcoin-QT is NOT running, remove your wallet from the Bitcoin-QT folder.
Start Bitcoin-QT and create a new wallet.
Copy a receiving address from the new wallet to somewhere.
Close Bitcoin-QT and move the new wallet to the USB stick.
Restore your Wallet backup, and start Bitcoin-QT
Send the amount to be gifted to the receiving address you saved before.