Different can of worms, but I don't have a problem with couples who request no children at a wedding. This couple have obviously included children (which is lovely) so as far as I am concerned they need to accept that a BF child will be BF at the wedding. I do find it offensive that the bride - or anyone else - is telling you how, when or where you can BF.

I don't know your DH, but I know I would prefer to respond to the email myself rather than have my DH deal with it. Maybe your DH is better at dealing with these issues than mine is! I would call the bride and very politely tell her that you are somewhat offended by her email and that whilst you understand some of her family are 'conservative' and as such you will be discreet in your feeding ( I'd mention the new dress here), you are not able to cover your DS and you can't predict where you will be when he requires a feed. I would also have to say something about not feeding in church and point out that god made breasts for feeding babies and you are sure he won't be offended. I would finish by telling her that if she does not wish for you to attend the wedding, understanding that you will BF and others may notice, then you will stay home. The ball is back in her court!

I would try to approach her in a very reasonable manner. I think if you speak to someone driven by anger or distress it is far more difficult to express your point of view. Good luck, I hope you can sort out an understanding of each others views and all enjoy the day!