I'm close to the SIL who was married to xh's dB. (So doubly an xsil now I suppose!)
We always got on really well superficially, but only bonded properly after we both dumped our hs (brothers).
My ex banned bil & sil from ever contacting me again when we split; bil was quite happy to go along with this, & sil couldn't face the WWIII that would have resulted in staying in touch, so she distanced herself too. That hurt, tbh.
A couple of years later she ditched bil for being a controlling twat, & in the aftermath got in touch with me to apologise for ghosting me. We - warily - met for lunch, & three bottles of wine later, we'd laughed till we cried & realised how much we genuinely liked each other.
We've been really good mates ever since - despite living in different countries now, we get together every chance we get for a day out/weekend away & stay in touch regularly online.
(The fact that the ghastly Brothers Narcissist, our respective xhs, pare baffled & fumingly irritated by this is also a bonus...
).
My other sil, xh's dsis, I haven't spoken to since the split - she obeyed the 'ban' on me. She quietly sends the occasional discreet, friendly 'say hi to Corvus' message via my dc, to whom she's an amazing aunt, but she's too nervous of upsetting her dB to contact me openly, so I'm happy to keep my distance & not drop her in the shit with her family.
As for my own db's dw, she's pleasant enough, & would probably say the same of me, but we have absolutely nothing in common. 10 minutes of small talk about our respective teens & we're all out of conversation! But she & dB adore each other so it's all good.