I'm really sorry to hear about your MIL - as has been mentioned, maybe she was just shocked or having a bad moment.

We haven't told anyone yet - I'm a wee bit nervous (we are only 8 weeks 1 day), and want to wait until 12 weeks. I am sure my mum will be ecstatic (she keeps asking if we are trying), she will probably tell everyone else and we won't have to worry about it then (!), this is one of the reasons why we aren't saying anything yet in case she lets slip because she's so excited! Also, our 12 week mark is my mum's birthday and we thought it would be really exciting to be able to tell her then - it would make her day!

Hopefully your MIL warms up.
Rachel