Wow, that is a really bad cross beak!
We had a chick born with cross beak and had to do some clipping and filing too,
The birds are amazingly calm about the whole thing.
This chick's cross beak looks so bad, that I am not sure clipping, filing, etc is going to be a big help.
I will suggest that you try wetting her food and seeing if that helps her eat it.
However, you have to be very diligient with this. The food will have to be changed daily to avoid any mold issues.