This could very well be a problem going on in her abdomen, or scar tissue adhesions. I had a complicated c-section that made for a lot of extra stitching. My c-section scar puckers a little bit from the pulling of the incision from the inside. I do have some pain at the scar area with certain sudden movements- like when i lean over the wrong way, cough too hard or get pounded during sex at the wrong angle. Its not excruciating, just crampy or sharp for a second.
I was allowed to have sex 2 weeks after my c-section, but we waited a lot longer than that. I gave him orgasms other ways until i felt comfortable having sex. Given that i was so sore at first i was scared. Also, i had no feeling in my bladder for months and couldnt tell when i had to pee because the nerves were temporarily severed during the surgery.
If she wont go see her doctor about it- i would begin to wonder if she just isnt interested in sex. I was terrified, my husband had to wait a few months for penetration.