...I wonder why they never showed her or any of his kids? (which I'm sure he had)

and they only showed Pickles a couple times. I wonder why?

I don't know about Mel's wife, but I thought I heard that the reason they stopped using Pickles was a matter of economics. It was decided they could save money by not having an actress play her onscreen, so they just banished her to the legion of unseen characters!

Actually I believe 2 different actresses played Pickles. She did appear a handful of times.

I don't remember anything about Mel's wife, I just seem to remember that Alan Brady was married to his sister, and it was implied that he got his job that way.

He mentioned her a couple times. In one episode-I think it was "WASHINGTON VS. THE BUNNY"-he's telling Rob something and starts out by saying "Rob, the other night my wife wanted to go dancing, but I had to work late. Now, I love my wife, and I love to go dancing but...."

And in another episode he says to Rob "AND WHY DID YOU SEND HIM OVER ON A NIGHT MY WIFE AND I WERE ENTERTAINING OUR MINISTER"?

I don't know about Mel's wife, but I thought I heard that the reason they stopped using Pickles was a matter of economics. It was decided they could save money by not having an actress play her onscreen, so they just banished her to the legion of unseen characters!
Well then, that's probably the reason they never showed her (also Alans wife, come to think of it).