This is pretty clearly a mother-daughter duo.

The lady on the right is a mature (if short) woman between 35 and 45. She is married as evidenced by the honking big ring on her left ring finger. I'd assume she is the mother of the girl on the left and presumably has several other children.

The girl on the left is pubescent. She's no more than 12-13 years old. That's baby fat you guys are seeing.

The woman on the right is clearly NOT fat. her arms are slim as are her legs. She has an average hip to waist ratio.

She's only got what the gods gave her up top also. No artificially enhanced secondaries like lots of women do today.

She's wearing a shapeless wool bathing suit whose purpose was to conceal the womanly curves of the wearer. She appears to have a slight double-chin, but I suspectthat this is due to the excessively wide and somewhat forced smile she is exhibiting. This is what conspires to make her look fat to some modern eyes.

In point of fact both of these ladies are skinnier, in better shape and more attractive than 90% of the women I saw waddling though the mall last night when I was Christmas shopping!