Hi Joseph,
There are 2 on the vanity in the main cabin and 2 under/behind the TV. One of those is (obviously) plugged into the TV. We unplug the Wave Phone and that gives us another one. On Wonder they put in an outlet with USB for the Wave Phone, so we used that too.
We always bring a small power strip with us and a brick with 10 USBs for charging phones, watches, etc.
There is an outlet in each bathroom (one if you don't have a split bath) but that is only for shavers. There's a hair dryer in each room already, no need to bring one.
I would advise you to look at the list of things you aren't allowed to bring and plug in too.
Cheers!