Instagram images extending outside the frame

Hi,

I’ve been helping to set up a page for a friend, and I used IFTTT to send her Instagram pics straight to her page. The problem is, each time an image posts, it extends outside the main frame/border of the page, as you can see in the top pic here.

In order to fix these, I have to go into each individual post, go to the advanced settings of the image editor, and change the max-width from 600px to 550px.

I’m sure this is a simple fix, but can someone help me figure out where I can set this up so they always come through at 550px so I don’t have to fix each one?

Thanks!