I don't know if this was done already, but I wanted to post my own thoughts on this.

Personally, I kind of put her in the middle of both of the groups. 

Here's my reasons:

First off, in the far future she has her own court that aren't kids of the Inner or Outer senshi. So if she was in either, she wouldn't have her own separate court like that. But I will agree that she is in fact part of her own Inner Court, I just don't know if there is a future Outer court made of new Senshi.

Next, she is really young and if she was in either group she wouldn't make as big of an impact due to her being so weak. Plus, she is very inexperienced despite all she has done to help Usagi. In fact, I think she's supposed to learn from both senshi groups so she can lead her own group in the future and become the ruler after her mother becomes Cosmos.

And finally, it is very heavily implied (I think?) that she is not part of either group to begin with. She was just supposed to help Usagi, and then after that went back to the past to become a Senshi. She is learning from the others as an outsider, not really helping all that much but is still important to both groups. And in the end, once she learns everything she needs to know (or gets old enough) she will have her own court to lead outside the two previous groups.

...But those are just my thoughts. I'd luv to hear what others have to say on this~ 

I agree with you here. Chibs is really not a part of either planetary group, Inners or Outers. In the past, she acted as Sailor Moon's apprentice, and I think hung out more with the Inners. She's just getting ready for her future role as the next Sailor Moon, leading the Sailor Quartet as her inner court and possibly an Outer Asteroid court (or at least, I like to think, though canon does not confirm this) as well. As she gets older, she will be more powerful, and train with the future Senshi instead of in the past.

That's just my two cents. But yeah, I think you sound about right.

Isn't the whole Inner/Outer classifications mostly a fanmade thing? I don't remember the series really officially saying they're officially separate from each other.  And am I the only one who keeps thinking of inner & outie belly buttons when people talk about the classifications?

I just thought she kinda stood in the middle, drifted toward the inners because sailor moon = past life of mom; given she is a senshi in training and she gets her own group later on.

@Neon Genisis: The manga states that Uranus, Neptune, and Pluto are part of the Outer Guard. Their group is definitely separate from Mercury, Mars, Jupiter, and Venus--though this is really only true in the Infinity Arc (and in the past as well). In the Dream Arc they are sort of "reborn" (Hotaru states that "they are not who they were before,") and at this point the two Senshi groups drift closer together. I'm not too sure about the anime, though. And Chibs is right in the middle/not part of either group.

In that case, I'm going to have to agree with the consensus here that Chibi Moon is likely in between the two groups as she ends up getting her own team, the Sailor Quartet, later in the manga.

I feel she is more part of the outer group just because of how she came to the past. She has great friendships with the outers. More than the inners it seems. 

But then again she does fight along side sailor moon and theven inner scosts  ore often.

So well...i dunno.

In my headcanon soup, Chibs is part of the "next" generation of senshi, and so it's kind of irrelevant to where to place her in terms of Inners vs. Outers among Usagi's senshi. 

Each generation of the Serenity line has its own group of senshi that get reborn in a giant, revolving cycle.  (I haven't yet decided how many generations are part of the cycle yet. Eight? A hundred? More?)  I think that Queen Serenity in the Silver Millennium had her own senshi, too-- we just never got to see them since we didn't see enough of Silver Millennium in the show, so they could be dead already by the time we meet the queen in the flashback episode of Classic.

So eventually, when Usagi and her senshi pass on, the mantle of Sailor Moon/Serenity will pass on to Chibiusa and the Asteroid Senshi, her equivalent to the Inners.  If Sailor Moon had existed in the Silver Millennium, and the Dark Kingdom hadn't destroyed everything, I think that something similar would have happened between the Queen and Princess, with the Princess ascending the throne at her mother's passing.