Thank you everyone for your replies and good advice, I've always loved having 2 girls and I never thought that it would come to this, especially now that they are grown up - supposedly.
One of my daughters rang me yesterday about something completely different (completely skirting the argument etc and avoiding mentioning either her sister or wedding plans), and we had an ok conversation although a little strained. I have to say I was relieved that at least she seems to be (a) talking to me, and (b) just getting on with her life! She is the level headed one who has always listened to advice and not really rebelled.
The other one is very hot-headed (a bit like me) and has always done exactly what she feels is right, although at times has come back and said things like 'you were right about that Mum', so I hope that eventually she may come round to things.
I am anxious however that things will never be the same between the girls after this - some very venomous things have been said and cannot be taken back - and also that I have lost one of my daughters for the moment - hubby says she'll need me before I need her though! his typical way of simplifying life
I know it's early days, and I also agree that maybe writing a letter will be the best way forward. I also can't really see the problem at all of them getting married quite close together (other than finding the money!), it's like there's some unwritten rule somewhere which I am obviously not party to.
I really appreciate the support you have all shown, (and am now crying again...), I don't feel that I can discuss this with anyone else right now, so your help is invaluable.
So thank you all very much, you are all so kind.
love Spadger x