There are several ways to handle...But I would handle it quickly! This is something you want to do and do it right.
I ask, what was your relationship with the bride prior? I try to get to know my brides, talking occassionally, attending some of her events (coordinator meetings, bridal fittings, etc.) I know that, that is a bit much. But hey, at the end of the day I have brought to their attention: time restrictions; poor lighting conditions; My needs to get the job done, their needs and how they can be achieved. A open level of communication that "we" can say what is on our minds.
I had a bride who was 29, had a stroke at 22, and it as you would have immagined, We talked extensively on how to keep the good side present as much as possible. She Cried when photos were delivered....Oh yes baby! And this was f-i-l-m. I have my share of plus sized brides this year...I put them in the same positions...I don't care!!!!! I have a job to do. If it is medically safe I am photo safe. Sure you do, do the things to cover, hide and light (shadow out) things you know that are not camera-lens friendly. However, she knows that she and her wedding party had faults prior. I would do as previously stated do 1 image and seek approval. Then I would have payment up front: 2 hours minimum. And a seperate contract....One that you win-win-win.