Complex sentence: Hedwig Elizabeth Charlotte of Holstein-Gottorp was one of the leading people of the Gustavian party, often visited ex-queen Frederica her in her house arrest and worked for prince Gustav to be acknowledged as heir to the throne.
Split into simpler sentences: Hedwig Elizabeth Charlotte of Holstein-Gottorp was one of the leading people of the Gustavian party. She often visited ex-queen Frederica in her house arrest and worked for prince Gustav to be acknowledged as heir to the throne.