Over the weekend, Jo celebrated her milestone day with family and close friends with a cake that hilariously read: "Happy 39 +1 Jo."
"I had the best night, it seems the older you get, the better the parties become!!" she wrote on Instagram.
Among the guests was Jo's MAFS bestie Belinda Vickers, who donned a red velvet matching set that delightfully matched her new red hair.
However, some fans were surprised to see (or rather, not see) Belinda's boyfriend Patrick Dwyer at the party.
"I see Belinda but where's Patrick," one wondered.
"Has Pat got the flick?" asked another.
In a previous chat with WHO, Jo revealed that when she finally stood up to her on-screen husband James at their final dinner party she found her voice.
"He sat there and his face changed. But he was still trying to argue with me, saying, 'Give me an example, give me an example,' with his arms crossed and his legs crossed. But when I found my voice, he pulled his head in," she said back in March.
The former MAFS bride added that she was disappointed with the man she was matched with.
"At the back of your mind, you know it’s a reality TV show, but I really thought I could meet someone who would want to fit into my life and compromise on things," she said.
"I don’t think he likes to be told by a woman. It wasn’t worth leaving my boys to be with someone like him."
She may not have found romantic love on MAFS, but Jo did come out of the experiment with a best friend in the form of co-star Belinda.
"I make some people happy, I make some people mad. Some people can be kind, some people can be mean, but as long as you are happy within yourself it shouldn't matter what others think or say about you," she wrote on Instagram at the time.
"I am so grateful for my #MAFS experience and I am so proud of myself for what I have achieved and done. I look forward to what my next chapter will bring."