oomis,
I agree that taking those pics is strange, but what can you say to get her to the doctor? Perhaps say that a full check-up is needed.
mewho,
I think that you can revisit that issue and tell her the problem. Better yet, the two of you (you and husband) should stand together while one of you speak with her. I have a feeling that she feels that he is OK with whatever she does. He has to voice/show his dissatisfaction, otherwise she will assume that he really agrees with her against you.
Shrek,
I think that you have to let her know that her unsolicited advice is not needed nor wanted. It may get her to be quiet. BTDT.
She may be looking to feel important and/or needed. Maybe find other ways for her to feel important, like take care of the kids, read books to them, help set & clear the table, etc.
Many parents are used to lording over their children and treating them like little kids. Some times, we need to break out of that rut OR change how that relationship works.