Sorry but I feel your SIL is being selfish.
Wow - sorry Tegam but that comes across as completely lacking in any compassion whatsoever. Brutal!!

The SIL would have just gone though a month of hell with her cycle only to find it a complete failure from an emotional, medical and financial point of view. Her world and dreams for the future could quite possibly be crumbling around her - giving her the grace of a few weeks to get through it / process it is really is no big ask from family and friends that have her best interests at heart.

I can honestly say that from my experience while cycling - the world outside my attempts to get pregnant simply ceased to exist, it's not selfish to protect yourself from pain and suffering when you are at your most vulnerable, its simply self preservation.

Bloom - if you want to open the lines of communication and reach out to her so you can both chat about your situation - perhaps send her some flowers that simply let her know you are thinking about her. I know after we had our first child via IVF, the pain and rawness definitely is dulled, you forget how damn hard it is at the time. I can assure you that when your BIL and SIL are in the right headspace, you will receive the genuine congratulations you are after. I wouldn't push for it earlier - otherwise all you will be getting will be an obligatory congrats - you don't want that.