Concerned for my co-worker

I am concerned about my coworker because she told her boyfriend last week they are getting married. They have been together for almost 6 years. During that time, he has never proposed. He has also told her he doesn't want a wedding and that he wouldn't marry her unless they had children. They have been trying for 2+ years to have a baby, but she is having some female problems. He also refuses to adoption even though she would love to. He has expressed concern that he wouldn't love the child as much as he would love his own biological children. She disagrees because he loves his ex's child who isn't biologically related to him and often spends time with the child. He has also told her that if they ever were to get married he would only get married at a courthouse because he doesn't like crowds and doesn't want to be the center of attention. To me, he seems very manipulative. So last week she sent him two dates June 6, 2020 and October 10, 2020 and said for him to pick one because that's when they are getting married. He picked one, but asked her what happens if he doesn't propose by then. She told him she doesn't care because that's when they are getting married. She has been engaged two prior times so she doesn't really care if they ever get engaged she just wants to get married. She also told me about a fight they had about a month ago where he was commenting inappropriately on a friend of his Facebook page. He didn't think she would see because that friend has her blocked on Facebook, but a mutual friend saw his comment and told my coworker about it. I am very concerned that she is going to end up hurt by this guy. She is so excited and so is her family. She has been asking me for a ton of advice since I just got married in July. I am hesitant to give any advice because of everything she has told me, but I also don't want to cause any problems. We work in a small office and it is normally just the two of us so I don't want to cause any issues as I am already concerned she is going to be upset if/when I get pregnant since we are trying to have a baby and it is a sore subject for her. Should I just keep my mouth stuff or give her limited advice?