I missed a opportunity to show my T compassion

. Today in session she told me shortly about her past abuse to relate, and I just got foggy and I couldnt say anything. Then i couldnt recoup and by that time she had went on to a different subject. What can I do to show her compassion so she wont think im an insensative person. Should I apologize or just try to make it up in another way? I feel horrible.