Remunerated consulting while being a PhD student
One way or the other, you will have to disclose the activity to your university. I can't think of any obvious reason why your university would not allow you to do consulting work on the side. But in any case, talking to your adviser about it would be the correct first step -- she may be able to tell you what her expectations are if you are paid as a graduate assistant at the same time, but also what your university requires of you in terms of paperwork.