Etiquette in a world where there is very little.......

I have an etiquette question. Last Saturday (April 17) my daughter turned 4. She had several gifts shipped to her seeing as how the givers were unable to travel to our house for her actual birthday. Should I have had her immediately call the givers to thank them for the gifts or should I have painstakingly sat with a newly christened 4 year old and helped her "write" out thank you notes? Any insight would be appreciated as I always thought that receiving thank you notes was the proper thing to do as long as they were sent out within a week of receiving the gift but maybe with the way modern technology is I'm wrong.....