How to proceed after academic dismissal from PhD program (plagiarism) and successful completion of master's? I was dismissed from a (Canadian) PhD program on the charge of plagiarism. I had muddled up sources, and the professor insisted I deliberately did it to get higher grades.  My student advocate informed me that plagiarism is plagiarism, whether intentional or not, whether only on a single line or not, and regardless of the professor's motivation. So, I admitted to the charge, while looking for ways to avoid a repeat and rebuild my reputation. 
I did inform the tribunal that this was a single sentence in a 22-page document, and that I was traumatized during this period as the state had taken custody of my two children.

The tribunal upheld the charge but recommended that the provost should consider a minor punishment. My advocate suggested I should not contest the recommendation of the tribunal. However, four months later, the Provost decided to dismiss me because I did not appeal the decision, and because I had failed to inform the professor of my personal challenges when I took the course.

When I was dismissed, I completed a master's program at another university with a GPA of 4.0/4.0. I discussed the plagiarism incident with my master's supervisor.

Now  I want to apply for a PhD Program in a separate, but related, area (my current supervisor does not work in this area and so could not supervise me), and I am wondering how to go about it since I am required to disclose all the post-secondary education attended. I would appreciate any suggestion on how I can navigate this muddy waters.
As mentioned in the comments, I do not think that you will be able to find a supervisor who does not know you well already if you have a record of dismissal for plagiarism.

You could try:


Telling the truth about your dismissal (lying or omitting that you were dismissed would likely be grounds for getting dismissed again).
Explaining, with evidence, why it will not happen again.
Do not mention the nature of the trauma you experienced.  Academics are not likely to consider any kind of trauma to be an excuse for plagiarism.  And they are likely to have strong opinions about how children are raised.
There is no need to give the details of the process leading to your dismissal.