Not angry anymore but concerned and sad

So here’s a little backstory before I describe this train wreck. My SIL is a horrible person. She’s actually mentally 12 and on disability. She is a junkie and alcoholic, her son has FAS. She calls people over to take care of him (her “friends” who are into the same shit). And has threatened to murder my MIL and BIL. They believe she’s medically abusing him also and so they’re trying to gather proof currently without him getting hurt. She has told multiple people she hates children and never wanted kids but is actively trying to get pregnant. Or was.

I’ve been trying for 16 months and have an appointment this month to figure shit out. I’m pretty sensitive about the whole situation.

So I’m having a good day, and then my fiancé gets home. He’s got this weird look on his face and then tells me to guess the news in regards to the current SIL situation. First think I guessed was that she’s pregnant. Yup. She came into his work today with his mom and told him she was. She’s been telling EVERYONE. He kind of laughed and was like “what bs is that, right?” And went about his business; I lost it immediately. I was having a hard time breathing and i was crying. This horrible, awful person is so bad to her current child, what will she do to the next? And then my thoughts went to how unfair it is that she can have another when I can’t. It broke my heart and it’s been hard to come back to the realization that her fertility doesn’t have anything to do with me. I’ve requested not to be told about her pregnancy (my MIL likes to vent) but only about the poor babies involved. I’m still hurt in so many ways but I’m trying not to be bitter and to be okay. And I’m still so worried about those babies, I had the one that’s actually here in my custody this summer for a while, and he’s such a sweet and happy boy, it breaks my heart to know what he’s going through. She doesn’t even pretend to care about him in front of family anymore, and it’s sad. ****She’s been ruled an adult but had the emotional capacity of a twelve year old if I’m not mistaken. She doesn’t have a guardian, and is free to do as she pleases. She also has proudly stated she’s a “slut” and will have sex in exchange for borrowing peoples cars (she had her license revoked for dui) and for other things. She kept telling my brother in law that his son wasn’t his (he is) but we aren’t sure about this baby. The whole situation is known and has been reported but no action can be taken because the baby doesn’t have any physical marks until we have proof. Also, I’m not sure about anyone else but I knew not to abuse children at the age of twelve.