At what point do I say something?

So I’m pregnant, and my SIL was a month behind me and lost her baby a few weeks ago. I feel so horrible for her and I know she needs some space. But my question is, how long am I supposed to stay away? I’ve also heard she’s been saying a few harsh things about me and my pregnancy, as well as lashing out at everyone around her and saying rude things. I understand how those feeling are normal/ natural, but to allow them to sever relationships long term feels really hard to me. Do I just stay silent forever? We’re a close family and I feel nervous to see them again and what she might say to me or completely try to ignore me. We were getting really close in the last couple years after many years of not getting along because of jealously issues she had toward me. I just really don’t want to go back there. Any advice would be great.