Your friend definitely needs some kind of attention and help.
This is not a false pregnancy or pseudocyesis. Women who experience that problem truly believe that they ARE pregnant. Your friend's confession indicates that she doesn't fall into that category.
This quote from SmilingBluEyes is right on the money--
It sure sounds as if she has a form of Post Traumatic Stress Disorder---a very real syndrome and the likely the result of her traumatic pregnancy/birth experiences. She likely mourns the losses of her concepts of the ideal pregnancy/birth and parenting experiences. This can really cause serious emotional distress for many women, and should be taken seriously and dealt with.
Not that I am a social worker or psychologist, but this is my guess as to what is going on. Still calls for professional help as she needs to heal herself, and thus, be able to effectively and stably parent her child.
Speaking as a nurse with both psych and postpartum backgrounds, she sounds like someone who is somatizing. People who feel helpless to express or receive help for deep psycho-social-emotional trauma can "relocate" their unseen needs to the physical realm, where others will offer the care and connection they crave. I must emphasize that this is rarely a conscious choice and even those who appear to be controling their physical signs and symptoms are often oblivious to the connection between what they are doing and their non-physical pain.
It sounds to me like your friend is in desperate need of comfort and nurturing and perhaps some serious counselling to help her get past the trauma she has experienced. She might be trying to relive the nicer parts of carrying a child in order to distance herself from the negative memories.
Please encourage her to get help. If she resists, still be there for her. Stay connected and perhaps she will develop enough trust in the future to deal with her inner needs more effectively.
She is fortunate to have a concerned friend like you.