Not a icensed psych but a master's candidatein counsleing who has just recently finshed a Psychological Assessments class.
What you need to know is that there is a thing called a "lie scale". Yes, it wants to know if you lie but not in terms of specific mistruths. What it wants to determine is if you are trying to "ffake good" or "fake bad". People in custody cases almost aways try to "fake good"- heck- if you didn't want custody of your kids you wouldn't be taking the test, now would you? People who tend to malinger will "fake bad", that is to say that they are worse off than they really are. if you wanted to remain on worker's Comp you might want to try to "fake bad"
My advice, not only as a master's candidate but someone who has taken the
MMPI-II three times in regards to custoy is to relax and be as honest as you can be. Of course you wantt o be seen in the best light possible.
When you take the test- don't linger over any questions, just answer as truthfully as you can and move on to the next question.
Know that the test is only part of your evaluation. There most likely will be clinical interviews and parent child observations as well as other tests.
Custody evals are stressful. Take really good care of yourself and try your best to realx.