The Mildner couple in my tree became foster parents of a young girl in the early 1900s. In 1912, they were sued by the birth mother of the girl for custody, but the judge ruled that the girl could stay with the foster family, after which she was apparently adopted by the family. The adoption was reflected in the change of the girl's last name between the 1910 and the 1920 (and later) censuses.
I had recorded the Mildners as foster parents of the girl. Now if I change the relationship as "adopted" I will lose the foster state.
Is there a good way of dealing with this situation other than through extensive notes?
Ancestry.com doesn't seem to provide a way to record date ranges with relationships, and only allows one set of relationships between a parent and a child.
In a comment to a question about names, Jane recommends creating explicit name change records.
How would one do that with Ancestry.com?