[esafak]

In other words, you can invent your own sign language because your child won't need to use it with other people.

[AlecSchueler]

Why not use a common sign language and give then a head start if they ever do want to use it outside the family?

[skeaker]

They might not have the dexterity required for some of the more complex signs, I would guess. If you devise your own gestures they can be much simpler.

[doubleg72]

No, the basics like hungry and please/thank you are fairly simple. The daycare my son goes to teaches all the kids sign language starting at like 6 months.

[schwartzworld]

The signs chosen to teach to babies tend to be pretty simple. Things like "more" or "milk" are very easy.

[jimmygrapes]

plus you can use it as a battle language for your clan

[rcbdev]

Exactly! Using a pre-made sign language is missing the point entirely...