Alma has a number of jars with resealable lids in her kitchen. Some are on the windowsill and probably contain baby food. To her right, as she scrubs her laundry in the tub, are some other preserving jars on the countertop. The presence of these jars on the countertop indicate the lack of a refrigerator in the house. So keeping the jars of baby food on the windowsill would have kept them cool and safe until they were used within a day or two. The Mason jars on the countertop would have been stored in a cellar or cool pantry until needed, and because they were "preserved" they could be kept for months or years.
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Two things about this kitchen stand out to me as being out of place.
That electric range is very slim, modern and not even second hand.
That plastic laundry basket was never available in the sixties.
It would have been wicker.