Email Reinna at firstname.lastname@example.org
Letters could be written to Reinna at:
Casilla de Correo 1
CP 3500 Resistencia
Be sure to add the appropriate postage to your envelope.
A FREE way of writing to Reinna is to go to www.dearelder.com and send a letter to her via the "Pouch" system after creating an account.
Please do not send her boxed packages. You can however send her things in padded envelopes. Apparently those don't have to go through quite the customs shakedown that packages go through.
You can also email Reinna at email@example.com knowing that she may or may not respond right away to your email as she only has an hour a week when she can go online to send emails.