I am carrying this guilt and wanna be woman to woman!

Would it be wrong for me to contact the mother of his 2 kids behind his back to reconcile or atleast start somewhere for our children to have a relationship growing up? I have major guilt inside me! It's weighing on me

Back story: Aug 2015 I got into a relationship with my man that had 2 kids with his ex, I was fully aware of the relationship with his bm. Relationship came to end, she moved out in Feb 2015 and moved in with HIS best friend that summer, (during that time she would text my man to drop me and to come back home with her and their kids😑😑😑. That didn't go down.) So the 2 of them got stationed in San Diego and left the 2 kids here with her mom. we would drive 3 hrs to see the kids 3 times a month. She would never agree for the kids to come to our house atleast or meet halfway. I would see my bf go thru a rollercoaster trying to be on her good side just to see his kids that went on. Dec 2015 I got pregnant. At the time we had one car so we would travel to see the kids but I would go to the mall and respect the boundaries of the bm mom's house. Her mother then saw I was respectful, no drama, and invited me in. From then on it was "how dare you bring your pregnant gf to my mom's house?!" Blah blah blah. SHE WAS LITERALLY MAD ABOUT EVERYTJING BUT DAYS BEFORE BE COOL ABOUT IT ALL. EVEN HER MOM TILL SHE TURNED TOO. Now while trying to care for our newborn Sept 2016 and wanting the kids to interact, we traveled again to see the kids. She got mad about that, mind you she's now pregnant with her husband (his bff since elementary, ex bff now) we were all invited to bday for his son and then 2 days later recieved from the bm saying she was mad me and his 1 year old son came along and that he was apending all his time with his other child and not enough with the other 2, whom were playing with their friends at a bday party! But would never let us have them alone it always with her family's supervision or nothing. it was damn if you do damn if you don't.

Fast forward they are currently married have a child together and have HIS side of the kids visit and have her 2 kids with them and has cut off all ties to my man and his whole family to be able to have any type of relationship with his kids. now I'm carrying this guilt that my man doesnt know about, im tired of feeling like we have 2 fam members that were not allowed to talk about or even enjoy because of the bm ways of having her own little happy family. I know it's not my fault but I don't want my child to grow up feeling a missing piece. I show my child pics of his siblings so he knows who his fam is. I just want to be mature and send her a msg being woman to woman about it all and just start small and send pics so our kids can see eachother and hopefully progress up from there. She recently unblocked me and I saw a few photos of the kids and it literally made me cry😭😭 just to see how much they look like my son/their brother and how much they have grown up! Everyone keeps saying just leave it alone let God handle it, the kids will find out the truth. But really you can't control what is being fed to the kids mind at this point. I'm tired of seeing my man have less emotions to certain things. SOMEBODY TELL ME SOMETHING! WHAT SHOULD I DO? Am I wrong? ** we didn't go thru the court because at one we had good communication and she didn't want to go thru the systems now after all this I feel like we would lose either way.