Your Tamagotchi character has to be on generation 2 or higher to visit its parent, and generation 3 or higher to visit its grandparent. If you've just started or restarted your tamagotchi in the past week, it's probably on generation 1. If you activate the meter icon in the top left corner of your tamagotchi, then go down to the fourth screen where it says Gender at the top, the generation number is listed at the botton. 1G is first generation, 2G is second, and so on. When your adult tamagotchi has a baby, either through mating by connecting or mating by accepting the matchmaker's advice, that baby will turn into the next generation. If your adult was first generation, the baby will be second generation (when the adult leaves the baby in your care).
Go to the TamaTown site and click on the Parents or Grandparent's house. A password prompt will appear.
Quote from TamaTown parent / grandparent house online help:
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Before you can visit your parents / grandparent, you need to get a password from your Tamagotchi toy.
Here's how:
1. On your toy go to the Friend list icon, and press the (
button to select it.
2. Then, use the (
button to select "Family" and press the (
button again to select "History."
3. Select your grandparent, and press the (
button. This should give you a password.
4. Now take the password you get from the Tamagotchi toy, and enter it here!
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