Get over it, we don't need more Mother representation, the other characters aren't as important as Ness and Lucas anyway.
Hi. How 'bout you play the games before making ignorant comments like that? Kthnxbai
N-E-WAYZ... I see where the original poster is getting at... so...
OK!
Mother got 2 playable characters. I was hoping for three, but hey, I was hoping for a forty man roster, and I guess that at 35, 2 is ok. If you want to get Metroid into this, at least Samus and Zamus are totally different... eh... I mean, besides being the same person and all, their movesets and Final Smash are all totally different. While Lucas and Ness get their handful of differences they're still similar characters. Besides that, none of them has PSI that corresponds to them. Except PK Flash. That's a con in Mother representation.
Keeping with the Metroid argument? then, we get one Boss. Ridley at least appears twice. In different forms. DON'T bring Metroid into this. (OK, I've been avoiding spoilers, though I wanted to know the Mother repping in SSE) Although Metroid is a larger series, so it deserves more Bosses, so I'm not complaining.
However...
WHERE ARE MY TROPHIEZ?!?!?!?!?!?!??!!??!?!!?!??!?!?!?!?!?!
I CAN'T EFFING believe there is no ****ing Paula Trophy in Brawl. WTF? The chosen four all got trophies in Melee, and now only Jeff gets in. The only reason I've always resented Ness in Smash is because he took Paula's moves, pretty much closing the door to her in future Smash games. I was content that she got a trophy in Melee, yet mad she couldn't even be cloned, instead of Dr. Mario or Pichu. Or both.
And now, there's no Paula trophy?

I was hoping she'd be an Assist, and she'd use Pray
The Mother series is not overrepresented, nor underrepresented. But it is poorly represented.
Why?
2 Main characters who can't use their own PSI
1 Assist Trophy when the series has been in since 64 (then again, ATs seem to be spread among the NPseries more than being additional reps for the playable ones)
They include Ness, yet include Pokey in his old form, and no Giygas.
Paula, Poo, Duster and Kumatora don't get to at least be Trophies so we can stare at them in 3D.
Etc.
This is only apparent if you're a Mother fan. If you're not you'll just go "Blah blah, only deserved one playable, blah blah, unimportant series, blah blah..." They are hits in Japan, and amazing, breathtaking games.