I could not prove the Years had feet — Breasts

Breasts, like Dickinson's pimples and freckles, would be something notable for their growing. The clue is "something awkward in the fit" in line eleven. We need to find out what that something indicates.

Dickinson felt fine about her breasts, but they kept growing. She had no problem with that and smiled upon them, except the awkward fitting of her clothes. Don't hurry to laugh at the answer. Check every word she used.

I could not prove the Years had feet－¹
Yet confident they run
Am I, from symptoms that are past
And Series that are done－

I find my feet have further Goals－⁵
I smile upon the Aims
That felt so ample－Yesterday－
Today's－have vaster claims－

I do not doubt the self I was ⁹
Was competent to me－
But something awkward in the fit－
Proves that－outgrown－I see－

(F.674/J.563)

[1] Years:: year rings _{(OED n.1 4c)}, hinted in line 2 to 4.
[2] confident they run:: she was confident that year rings will grow.
[3] symptoms, past:: the nature of year rings.
[4] Series:: a set of concentric circles, a hint on year rings.
[5] feet:: foot, the lower (usually projecting) part of an object, which serves to support it; the base _{(OED 10a)}; the bases of her breasts.
[6] aims:: round targets with concentric circles like year rings.
[7] felt so ample Yesterday:: they were ample already, she felt.
[8] vaster claims:: they demanded to grow greater.
[9] not doubt, self:: she had no problem with that.
[10] competent:: suitable, adequate, or sufficient, in amount or extent _{(OED 3a)}; the size of her breasts was competent to her.
[11] the fit:: correctly shaped clothes.
[12] Proves, outgrown:: the outgrown of her breasts was proved by her fitting clothes, an awkward thing for her.