I don't really think my clothing has ever defined me as a parent. I think my clothing more reflects who/what I am as a "person who also happens to be a woman" (whether or not I've been a parent at any given time).
What I've always hoped I would be "as a parent" has been to be a good role model as that "person who also happens to be a woman". I've hoped I've been able to be a good example as a person and a woman for my sons and my daughter.
I figure, clothes show little about how strong, caring, smart, giving or capable a person/parent is; so, to me, the "external thing" of what we wear is more about showing whether we're people who aim to dress in a way that makes us look our best and/or positively reflects on whatever sex we are.
So, I suppose, my clothing defines the kind of parent I am by reflecting a person who aims to dress appropriately for the occasion and dress in way that is most flattering to me, as both a person and a parent. In other words, I guess it shows I'm a parent who hopes her kids will see that it's good to aim to look our best (because we feel better when we do), and dress in a way that's right for us - not that's "the height of fashion" or "the latest thing" that "everyone is wearing". Equally important, I've always hoped my kids would see that a "person who happens to also be woman" can be what she is "on the inside" and yet still be feminine on the outside. Why do I want them to know that? Because I'd like to think I've raised some next-generation grown-ups who won't look at women who are feminine-appearing/sounding "on the outside" and assume they can't possibly be strong or smart or logical. :/