Complex sentence: The collection was formed by Evelyn De Morgan's sister, Mrs Wilhelmina Stirling, who wrote several books under the name A.M.W. Stirling, and was previously on display at her home, Old Battersea House.
Split into simpler sentences: The collection was formed by Evelyn De Morgan's sister, Mrs Wilhelmina Stirling, who wrote several books under the name A.M.W. Stirling. It had been previously on display at her home, Old Battersea House.