"I actually have respect for how @meganfox is finally living her life for herself & leaving her children out of her public life at this young age," Marcil wrote. "I used to hide Kass from the public when he was young & never once spoke about our court case to kass or publicly until Kass was grown & insisted I stop lying to protect."
"Megan finally living her life for herself is in itself a gift to her children," she added.
On Friday, Marcil also shared a throwback photo of her and Green when she was pregnant with Kassius while reflecting on 9/11.
"Sept 11... I was pregnant with Kassius and headed to NYC. Kass' dad was driving me to the airport. We received a call from Nana frantically saying 'Is Vanessa already on her plane?' 'Turn on the news' New Yorkers' lives changed forever... #nycneverforget 📸 by @kymberly_marciano," she wrote.
When a follower commented on the photo that they thought Marcil still loved Green, the General Hospital star responded.
"I was never in love with him but I am very proud of the fact that my son loves his dad unconditionally and has chosen to forgive," she wrote. "I celebrate Kassius' love for his father and remain extremely grateful that Kass was finally invited back into his father's life and was able to meet his youngest brother for the first time & finally start seeing his other two siblings again. 5 years apart with no explanation is devastating for children. For siblings. My son is also an incredible & protective big brother."
"12 years ago I was served legal papers and then spent 8 years+ defending myself and my son in custody court in response to his father & his stepmother trying to get full custody (that means I would have seen my son four days a month) and then asking me to pay them child support," Marcil claimed at the time. "Kass has never met his youngest brother and is not allowed to know where his bio father, stepmother and three younger brothers live. Custody cases hurt the children only and the truth shall set us all free. Put the kids first you guys. ... Kass has been truly heartbroken since being cut out of his other families lives with NO explanation."