Announcing a baby to siblings who can't have them. Help!

Hi IM's.
Short story, i'm the last of four siblings. I'll name them by number. We all live in different states.
I am the only one of us who can have a child.

No1. 35yrs old. Self-centered. The eldest is not married and can't carry due to drug use and is also mentally ill because of that. No1 will fly off the handle at any time during a PG conversation, will be emotionally abusive and nasty to the point of making threats and raising their hand, but hasn't hit yet. Disrupts all family gatherings including my wedding where 1. walked out crying and angry, because quote, "She is happy". I try to put up a wall and not to let it get to me, but it's hard being such a personal attack on my life and husband. And deliberately doing something, like kicking me on the couch continuously to start an argument. Childish I know.

No2. 33 yrs old. Conniving. 2 is very into mind games and loves to get info on a person, then another person and swap stories to sit back and watch a fight brew between the two, including my husband and I. We are pretty clued on to it now, and don't allow ourselves to be anything but happy in front of them, so that they move onto the next person. (Cue No1 to spit the dummy because we are happy again in a family situation) .2 Doesn't like kids.

No3. 30 yrs old. Emotional. Gorgeous person underneath and has been basically my twin and protector forever. They would do anything for anyone and its all for the good of society. That is until they came back from Iraq and has serious PTSD. Now No3 can be normal about something, then suddenly snap into anger and depression and can cry for hours, but screams if anyone goes near. Found out a year ago they can't have kids due to childhood accident that wasn't detected. Is completely crushed and deeply depressed, but is still lovely to talk to. Only after this latest childbearing blow, can No3 be easily manipulated by the other two.

No4. 26yrs old. Me. Simpler life country girl who loves her animals, husband and looks for the beauty in everything. Am easily hurt and wear my emotions on my shoulder. My nickname is Sunshine from my boss and have always been quiet, just observing the world. I live somewhere that I don't want to be and that is taking its toll on me emotionally and i'm scared that I will be sucked into depression as well. Husband is resistant to move, but hopefully he can understand what's happening to me, inside.

I got a phone call from No1 recently abusing me of being disrespectful and a C*** for posting on FB, my excitement on my best friends pregnancy. For this I was labelled heartless, not in the family and that they hate me. I dealt with that alright with just a few silent eye rolls... until No1 involved Emotional No3 (my closest sibling) and said how they are devastated and hurting badly for what I posted on FB. I said that it's my age group and that is happening a lot around my circle of friends and it's just FB, its not a means of intentionally hurting anyone. That set off fireworks, the repercussions of answering back is not worth it, but i'd had 25 years of gutfull.

We have been contemplating having baby for a year now, I feel excited and exhilarated inside and our Parents are SO ready to be grandparents, but how can I handle the other 3 without being 1. lashed at, 2. being told they don't care and 3. hurting so badly that they will crash even more.

My parents are super supportive and talk me through anything I need help with, and to phrase things to avoid clashes with the others. Thank god for them!

So: What would you do?