Is there a way to insert blank columns in output with google sheets query?

Put the empty columns as literals in the query - cannot really be empty though, must contain a space like this

=query(Sheet!A7:C, "Select A,' ',' ',' ',B,C where A='Order'")

I tried a version of ttarchala's response, just giving each blank column I wanted a different "signature", if you will:

=query(Sheet!A7:C, "Select A,' ',' ',' ',B,C where A='Order'")

Note the 1, 2, and 3 spaces in the quotes.

This worked - sort of. It gave me column A, then three blank columns, then B and C. However, it gave me a header row (which in my example I didn't want), and in the blank column headers I got:

| " "() | " "() | " "() |

Which was odd, but understandable. I hid the formula one row up and merged cells across A through C. Which left me with a nice blank cell. I took advantage of the fact that the output from query() can't be shown across merged cells.

This is of course a very specific solution - I had an empty row above my output that I could use and abuse for this purpose. But I thought I would mention anyway, just in case it gives a direction for better ideas.

UPDATE

Adding:

... LABEL ' ' '', ' ' '', ' ' ''

.. to the end of the query zeros out those odd headers that are added and removes the need for that extra row. This tells the query that the label for ' ' (one space) should be nothing, ' ' (two spaces) nothing, etc. This results in no header row.