No of course not, perhaps she thinks you will get more upset and that will scare her more.
My dd is having counselling and treatment for a recent major trauma. She told psychiatrist that she couldn't talk to 'mom because she cries and dad just gets angry about it'...we felt terrible but doc explained that its perfectly normal and healthy as the child parent relationship is so close.
Are your parents happy to take her? Perhaps you could all go and your mom just go into the room with her.
Well done you for raising a child who knows how to manage her fears, work out what she wants and needs and ask for it. I know my heart would be breaking but really, a bad mother wouldn't care. You care.