Under a "normal" suicide, then yes maybe there is a case for arguing that it was that person's decision to take their own life. But in this case the text messages clearly show that Conrad was having doubts about his decision and it was her response and her words to him that resulted in him being dead. So you can't say that she isn't to blame, there's clear evidence to show that without her interference, he may well still be alive
Conrad tried to kill himself four times before Michelle's involvement including just two months before he successfully did. There's no evidence that she told him to get back into the truck, she told one of her "friends" that two months after his death, she also told them at least 4 other versions not mentioning this.
Michelle reached out to Conrad's best friend Tom Gammell at least 5 times about his suicidal thoughts between 2012-2013. She asked Tom how he was doing after his first attempt and he said he was fine, Michelle said but he just texted me saying he is going to kill himself. She asked Tom to help him, i don't know what Tom did he didn't say at trial but whatever it was it didn't help as he was still talking about killing himself every day.
Conrad's mother wouldn't admit at trial he was ever suicidal. She said he had "a lack of sleep and social anxiety", she also referred to his first suicide attempt as "He was not feeling well", then when pressed as far as she would go is "he took some tylenol". Having a suicidal kid is one of the toughest things a parent could go through so i don't blame her but she was clearly in denial about his problems which couldn't have helped.
A doctor of Conrad's wanted him to go into an in-patient program for his suicidal thoughts, his mother said no. This was during the summer of 2013 (a time his mother tried to say he was fine during) long before Michelle was encouraging him to kill himself. What this shows is his mother was confronted with his problems several times yet she did little to help him she rejected help when it was offered, the point is even if Michelle told her it likely wouldn't have mattered. Again not attacking his mother, she likely just believed Conrad over the doctor like many parents would have done sadly.
Conrad stopped taking his medication at one point and self-medicated with weed, his mother admits this at trial. His mother kicked him out the house at one point for smoking weed.
Throughout the trial his mother makes out that Conrad wanted to see a Behavioural Therapist. The Defence Lawyer points out texts between Conrad and his mother that shows she is lying. From the texts it seems like he didn't want to see this person at all and it was his mothers idea. She is clearly denying it because she is arguing he was never suicidal he just had social anxiety and sleep problems. Conrad needed much more than that and i think her denial about the seriousness of his issues played a major part in his death. Conrad didn't tell her he was seeing a therapist in the months leading up to his death, she only found out after seeing it on insurance forms after his death in her own words. Why would he hide that from his mother? Probably because she rejected help for his suicidal thoughts when he was offered it. He claimed to Michelle his mother saw a suicide methods page opened on his computer and said nothing. Initially i dismissed that before seeing the trial, it sounds like she was in denial and i fully believe that happened. Long before she encouraged him to commit suicide Michelle talked to a therapist about a suicidal boyfriend (Conrad) who she didn't know how to interact with as he had no support system other than her. It's hard to disagree with that when you see everything.
What she did was awful, she deserves to be condemned morally but there's no way she deserved to be convicted when Conrad was extremely suicidal and the people around him (unlike Michelle who had only met him a few times) did next to nothing when informed multiple times. This is without even going into the motive about her "friends" which makes no sense since their relationships didn't change after Conrad's death. According to Lexi, Michelle actually asked them to hang out LESS after Conrad's death. And she definitely wasn't trying to help Michelle she was clearly annoyed to be there and said some brutal things about Michelle.