Again, thank you for all the responses.
I have to say that it isn't just my views and feelings involved, obviously DH has to have a say so what I'm telling you here, isn't 100% my opinions on it, they are a mix of both.
I suggested to DH last night that we at least arrange to go round there and have a discussion about the safety measures she intends to put in place. I think a fair hearing is deserved before a decision is made on our part. However, I and DH do not feel that we were given a fair hearing on our feelings about the changes. DH feels that as this is the case, why should she have a fair hearing? My feelings on it are that she deserves an opportunity to discuss it with us as ultimately it is the children who will suffer.
I really, really do not have an issue with her having a dog. When the phonecall came, I did say that it was their house so ultimately up to them. Doesn't mean I'm happy about it and it doesn't mean that I have to continue with the arrangements when they have changed without prior notice or discussion. I don't think it is too much to ask to at least have the courtesy of giving us a bit of notice tbh.
I don't beleive I am trying to control her at all. I am simply trying to work out a solution to a problem which frankly isn't of my making. As has been mentioned, if a bit of notice had of been given, it could have been talked about properly on all sides and an informed decision made. I haven't said anything along the lines of "get rid of the dog or the kids are out of here", I haven't laid down any ultimatums.
TBH I'm not overly concerned at this stage about the puppy. It is only 5 weeks old so spends most of its time sleeping. This is why we haven't withdrawn the children already because at this moment in time, it poses no immediate threat. However, nobody knows to what size it will grow, nobody knows what it's temperament is likely to be and we are still to find out what safety measures are going to be put in place.
DH has spoken to her this week about it and has said we need a bit of time to talk it through between ourselves. Again, no mention or veiled threats were made. He has just said that we will do what I feel the CM should have given us an opportunity to do in the first place; think about the pros and cons and discuss them.