open adoption

hi, i am adopting my foster son and when his mom surrendered her rights, she asked for an open adoption arrangement where she would get pictures and be able to see him occasionally. at first i was a little leary of the visitation but as i read more on this forum i realized what a wonderful gift this would be not only for my son, but for me too. the adoption is not final yet and now birth mom states she is only ready for pictures right now and does not feel she can have vists at this point. the problem is i have really gotten used to the idea and now am feeling disappointed for my son. i realize at a later date she may be more ready and i do not want to push something she is not comfortable with. has anyone had what started out to be a more open adoption and had the birth parent decide to close (except for pictures) the adoption. this is a strange emotion i am having and it is hard because my friends and family are sort of glad. i am secure in my relationship with my son and only think an open arrangement with his other family would be beneficial to him.