We shouldn't assume. But we know that there are dangerous people out there who delight in harming others. We have very specific terms for some of those. She appears to be behaving in a manner consistent with that sort of person.
That makes her sick in the head. It doesn't make her responsible for his suicide, or any other crime I'm aware of.
Ultimately the truth is for a trier of fact to determine, but the suspicion is a reasonable one given the facts before us.
Suspicion of what? … Wanting some else to kill themselves? Telling them to? I'm still not seeing her responsibility, or her crime. At no time did she deny him his right to choose his own course of action. So how is she responsible for the course of action he chose?
He extinguished himself. That's a clear sign of mental instability and illness.
So is her wanting him to extinguish himself. So, if his mental illness excuses him of responsibility, in your mind, why doesn't her mental illness excuse her responsibility, in your mind?
Also, mentally disturbed or not, there is NO EVIDENCE AT ALL that would indicate that he had lost his ability to choose his own course of action. And without it, there is no reason to assume that she had control of him. (Something that is nearly impossible to achieve.)
She urged him to it. That isn't necessarily a similar sign. And he had a history of that instability. She looks like a wolf, calculating her response to the death she urged. Her actions aren't necessarily irrational.
What she "looks like" to you, or me, is not particularly relevant, is it? Though I'm puzzled why so many here have jumped to that conclusion without even a thought to the possible mental instability she might be experiencing. Somehow his instability is automatically presumed tantamount to mind control while hers is simply inconceivable.