If you need to do this on a more frequent basis, you may want to find out if the recipient passes by an ATM whenever she goes outside her residence, and if she is willing and able to use an ATM to get currency.

If so, consider the following:

Find a bank is no service charge to maintain an account, and the lowest possible fee to use an ATM not owned by the bank (or is within the same banking company as the recipient's convenient ATM and does not charge a fee). Get an ATM card with a 4 digit password (verify with the bank that it will be usable to get currency in Korea). Mail the ATM card to the recipient, then phone the recipient to give the password. If you need to send money, just deposit it in the account, then phone the recipient that she can pick it up at the ATM.