Margareta Slots was the daughter of the Dutch merchant Abraham Cabiljau. Slots met Gustav in Pskov in 1615. She was at the time married to Andries Sessandes, who fell in battle soon after. In 1616, she and Gustav had a son; Gustav acknowledged her son and granted her an allowance. She married paper maker Arendt Slots and then gunpowder maker Jacob Trellow, and was given the estate Benhamn in Uppland, where she lived with her husbands, often asking for favours from the king.
In 1625, she was involved in an incident. The bailiff Jacob Galle threatened her with confiscation after she had prevented her tenants to take part in a construction work. She then visited Galle, asked if he had not heard of the priviligies granted her by the monarch and struck him with her stick, after which Galle was beaten by her servants. Galle died of the injuries and she was accused for his murder, but there is no mention of any punishment of her. Reportedly, she met Gustav only once (1630) since their relationship ended.
- Göte Göransson: Gihl Dahlström: Gustav II Adolf och hans folk, Bra böcker, Stockholm 1994. ISBN 91-7119-128-3.