Cameras positioned in places where one might be expected to see a person in a state of undress or engaged in some kind of intimate act, like a bathroom or bedroom, can indeed be a problem. A lot depends on the details here. What did you catch her doing? Note that it is not unusual or necessarily for teens to explore their bodies and try out things like masterbation. If that’s the sort of thing you saw, it might not be as troubling for her as you think. Again, the details would matter a lot.
Note, however, that if that is the sort of thing that the video captured, that could be a huge problem for you, as that could be considered child porn. In that case, you best see a lawyer before you discuss it with any counselor or anyone else.