My experience has been that no one cares for your possessions the way you would like. Sounds like you had a family antique that meant a lot to you. But because you love your sister, you loaned it to her with express directions to return it. Sometimes family members are lax in their attitude and actions. They feel that "you won't mind" just because they are family.
And sometimes things given to others are not viewed as important. If others had to secure them on their own, the items would be viewed as "valuable" and taken more care of. I'm sorry your antique was ruined. As a collector, I know how you feel.
Thanks for sharing. Some days are just more difficult to get through. But we find a way. Take care.
!LADY