It sounds like the two of you don't really understand where one of you ends and the other one begins. In fact maybe your whole family is this way.

Your reaction is your reaction, and her disappointment is her disappointment, for example. She can't seem to handle feeling disappointment without lashing out and getting people on "her" side and against you. That is so sad.

If she knew what was going on in your life, that you made a wise and responsible decision to hold off on having a child for now and, and how disappointing that must be for you and your husband, then she would have been ready for a less than ecstatic reaction from you. She would have been concerned for your feelings even before you reacted.

And maybe you could have foreseen the possibility of her getting pregnant first, since you are both young and ready for families.

But, then maybe this isn't the time for having a baby anyway, when your family isn't able to support both you and your sister. Your family is reacting in such a judgmental, hurtful, overly dramatic way. You and your sister are separate, different women. You are adults and both of you are right. Both of you are hurt. Both of you are entitled to your feelings.