No.729
Talking to yourself through grief is common; however, Schizoid related disorders tend over roughly 6 month period.
No.731
Get her to a therapist. Even if it's not schizophrenia it's a good idea for her to talk about her grief with somebody.
No.740
That doesn't necessarily have to be a mental illness. Maybe it's just taking her longer to accept her parents' deaths. Even so, I do agree with
>>731 since it's been so long and she should be speaking to someone about it if it's really affecting her.
No.747
How about you stop guessing around and trying to decide reality based off two or three external data points, and just talk to her about it until to find out if she's just talking to the photo to make it feel like she's talking to her dad, or if she imagines and perceives a real tangible live person in the room without being aware of doing so.