If I go to a chicken farmer, boots flecked with manure, bib overalls and floppy hat...and I consult with her on the best way to raise chickens...
Then she, in her immediate function as my consultant, is 7th house.
She may continue as my 11th house friend, my 5th house lover or neighbor in the 3rd. As a chicken farmer, I place her in the 6th.
But if my primary interest in her, in the context of the question, is as a consultant (I seek her expert advice), then she is 7th house. House assignment relies on Function.
If you are about to read a horary chart for a client and you find Saturn in the 7th, you might decline to read the chart, for the chart is saying that the astrologer is somehow disqualified. [deleted attacking comment - Moderator] But in the question clouded by Saturn in the 7th you are fulfilling that function.
In natal astrology I use Moon as principal symbol of "Mother." It doesn't matter if she is a good mother or a bad one, an expert mother or a novice. She functions as "Mother" and is represented by Moon, just as "consultants" fall into the 7th.