These robes are from a 1940s Christmas catalog, but Mother-Daughter outfits were popular well into the fifties. I found examples from Butterick, Simplicity, and McCall.
These Butterick patterns show girls’ styles as identical to the women’s clothing as possible, as if girls really were “little women.”
“Daughter chooses an identical coat frock to help Mummy on her busy days.” In reality, Mummy chose both their clothes.
Simplicity Sundresses, 1948
Mother and Daughter patterns might be featured together, as in the listings above, but they sometimes appeared on different pages, like these charming Simplicity sundresses with bolero jackets. In this case, the child’s pattern has been modified to allow for its shorter skirt without noticeably scaling down the appliqued flowers:
Sun or Swim Suits, 1950
McCall offered these Mother and Daughter playsuits on facing pages of the catalog:
The bloomers seem to work a lot better on the daughter! [Full pattern descriptions are at bottom of post.]
Mother and Daughter Matching Aprons, 1950
The daughter’s aprons had their own listing in the Children’s section; I have put both illustrations side by side to show how very similar the adult and child versions were:
My mother had more enthusiasm for Mother-Daughter looks than I had. In the 1950s, it was assumed that little girls would want to be “just like Mommy.” I had suit with a dark red jacket and a plaid, pleated skirt — just like my Mother’s. I was given a little toy iron that really plugged in and got warm (not hot,) and a little toy stove (ditto.) I didn’t need a little apron “just like Mommy’s” to see where this was leading. . . . And, even at age five, I had other plans.
More Pattern Information:
Mermaid Swim- or Sun- Suits
Robes 1290 and 1289