You will need something that uses the local wi-fi, and it needs to be a fast wi-fi network.
The Camera-A and Camera-B apps might do what you want. The Camera-B app is for the iPhone, but will work on the iPad in emulation mode. You need both. The delay may still be too much, but it's worth a try.
There is also at least one baby monitor app out there that should work. I don't remember it's name, but a search should turn it up.