Complex sentence: After the annulment of her marriage, Effie avoided Millais for some time, but eventually invited him to Bowerswell, where they were married in June 1855.
Split into simpler sentences: After the annulment of her marriage, Effie avoided Millais for some time. Mervyn Wiliams, "op, cit," The following year, Effie eventually invited Millais to Bowerswell, where they were married in June 1855.