Header is not working properly

I’ve just finished designing a website for someone, but for some reason the header on the link provided is not working properly.
I’m not sure if you can see it (as I can’t) but when my client looks at it from her end the header (image and purple to the sides) is discoloured, a much lighter filter over the top, is cut off (bottom part at the legs are cut off) and isn’t centred (sits off to the right).
From my end, the header looks perfect the way I made it, the right colour with no filter, doesn’t cut off and is centred.
I have no idea how to fix this because one, I can’t even see anything wrong with it from my end (have checked on other computers) and two, everything from the back end is correct. I even pre-made the header in photoshop.
These are the specifications on the header:
Position: default
Attachment: scroll
Repeat: no-repeat
Size: cover
Title background height: 300
Title background overlay opacity: 0.1
Title background overlay colour: #714c61 (this is the colour I’m using in the header and on the rest of the site. I used it here so the header wouldn’t discolour, and it hasn’t from what I can see but not for her)

The page I need help with: [log in to see the link]