Thank you ladies I really couldn't have handled it so marvelously without the positive feedback (Tracy thanks, sometimes you have to just serve people honey, as my mom would say *wink*).
Slapsappyhappy, wow I think Tracy is right you may just have to grin and bear it. That is the first time I have ever come across such a dilemma. Have you thought of mentioning to you FI that perhaps his nephew should be the ring bearer and wing man to the best man, since it is customary for the best man to make a speech during the reception and you would like it to be one of his friends that knows him. You can tell him it is kind of like him having two best men! His nephew and an adult friend. I don't know just trying to be as helpful in finding a positive solution as many of the ladies were able to help me.
PhillyBride: glad everything went well with your wedding and that everything worked out for me as well. Though we are paying for FSIL and her husband and baby M to attend our wedding, they really wanted to come but have been having a few financial difficulties so they asked for a loan to attend and they would pay us back, instead we told them we would pay all expenses and it would be a gift since they haven't taken a vacation since they married. I guess I should have mentioned this from the beginning but I didn't because I didn't think it mattered. Its an act of kindness separate and apart from what I was having an issue with. I would have purchased her dress but she insisted on at least paying for that, but I am purchasing her shoes and jewelry. But yes I do understand the jist of what you were saying about having a DW. Also I should have been clear I didn't mind having baby M at the reception just the ceremony was my concern.