She'll get through it. I had a similar experience, but it passed. I can't picture my daughter in my mind, but I can describe her and recognize her and, as it happens, she has aphantasia, too. Indeed, I only realized I did because of her. She said that, because she is autistic and has always known how different she is, she knew it wasn't just metaphorical when people spoke of "mind's eye" and "picturing" things. Remind her of how much aphantasia frees her from. I wouldn't trade.