"Scotch sister" meaning in English

{
  "forms": [
    {
      "form": "Scotch sisters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Scotch sister (plural Scotch sisters)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              105,
              118
            ]
          ],
          "ref": "1866, Elizabeth Gaskell, chapter 19, in Wives and Daughters, London: Smith, Elder & Co.:",
          "text": "[S]he had heard of the probability of her having a sister—(she called her a sister, but whether it was a Scotch sister, or a sister à la mode de Brétagne, would have puzzled most people)[.]",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A distant relation; possibly a cousin."
      ],
      "id": "en-Scotch_sister-en-noun-VW~aJ8Ki",
      "raw_glosses": [
        "(obsolete) A distant relation; possibly a cousin."
      ],
      "tags": [
        "obsolete"
      ]
    }
  ],
  "word": "Scotch sister"
}

{
  "forms": [
    {
      "form": "Scotch sisters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Scotch sister (plural Scotch sisters)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with obsolete senses",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              105,
              118
            ]
          ],
          "ref": "1866, Elizabeth Gaskell, chapter 19, in Wives and Daughters, London: Smith, Elder & Co.:",
          "text": "[S]he had heard of the probability of her having a sister—(she called her a sister, but whether it was a Scotch sister, or a sister à la mode de Brétagne, would have puzzled most people)[.]",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A distant relation; possibly a cousin."
      ],
      "raw_glosses": [
        "(obsolete) A distant relation; possibly a cousin."
      ],
      "tags": [
        "obsolete"
      ]
    }
  ],
  "word": "Scotch sister"
}