Baby at Wedding

There should be no need to say anything as parents usually know to take a crying baby out. I see it all the time.

And by the sound of your relationship with her I fear that telling her she should take the baby out will not go well !

Most new parents are very anxious about their baby crying & causing disruption, so the parents will probably be more keen than anyone that their baby leaves the room quickly if he/she starts crying. But I have met a couple of people who don't behave that way, In case your sister and BIL are like that, I would suggest approaching it from the point of view of their comfort. So maybe tell them you've arranged a seat for BIL right next to the door so that it is really easy for him to get out with the baby if he needs to. If you mix that in with comments about the baby-changing facilities at the reception, the quiet space that is available for when baby needs to nap etc, then hopefully they will take this as you being concerned for their welfare, while absorbing the reminder that crying babies need to be taken out!

Agreed that most parents would automatically take them out, but I have been at a wedding where a lady turned up with her 3 month old, which she had been told was not invited and then proceeded to sit right in the middle of the seating and it was crying right at the pivitol moment of the I Do, which we didn't hear!,I absolutely think it is ok to say something now, as not everyone thinks the same. i would assign him a seat on the end of a row nearer the back and let them know this is the case and simply say that you are sure they would take the baby out but you have assigned the seat to make it easy to do that and you would be grateful if they can ensure the BIL does take the baby out if it starts to cry. It will be difficult as you have a fractious relationship but it is your day so do you keep quiet and spend the whole ceremony worrying so as not to upset her, or do you mitigate it now so that she has a chance to digest it and be respectful of your wishes for your wedding. Wish you luck, take the plunge and get it out the way ASAP