ok Firstly, I agree with everyone else, I think just sit her down and explain how greatful you are for her support and that you appreciate that she is supporting your want for VBAC, but explain that you may need another cs and all the details, before she can say anything jump in and tell her that you are 100% fine with it, and will just be glad to have bubs here happy and healthy.

HTH

BTW whats IUGR?