Children at the Reception

Hey Girls....I am having a problem. Maybe I am making too big a deal of this but its bothering me. I have a very small family and all 3 of my young cousins are going to be apart of my bridal party. (BY the time we get married, the two boys will be 9 and 7, however my flower girl will be 2 years old.) They are the only children that I want in the wedding and that isnt a problem with fh. The problem is that his side of the family which is much larger then mine has about 5 small children in it. (when we get married they will be about 1 1/2-5) His mother is saying that they have to be invited. I have never heard of this...since when does the bride have to be forced into having very small children at her wedding. Last time I checked I was paying for this and I dont think that it is appropriate for small children to be there. I told his mother that this was not romper room and that I didnt think it was a good idea. She said that it was going to cause big problems with the family if they werent invited. She said that I should leave it up to the parents if they want to bring them. I dont understand why do I have to worry about caring about how they will feel if they dont really care about my feelings. SHe said that it wasnt fair that my family's kids would be there...but my argument to that is that they are in the wedding party and they should be there. In addition they are going to be older with the exception of one of them. I dont know what to do please give me some of your suggestions...am I making too big a deal of this???