Name	Lifeboat from Titanic	Lifeboat to Carpathia	Confidence Level
Astor, Mrs Madeleine Talmage	4	4	5.00
Bidois, Miss Rosalie	4	4	5.00
Thayer, Mrs Marian Longstreth	4	4	5.00
Widener, Mrs Eleanor A.	4	4	5.00

Emily Borie Ryerson’s American Inquiry account on page 1107 lists Mrs. Astor, Mrs. Thayer and Mrs. Widener as being in lifeboat #4. Mrs. Ryerson account definitely places her in #4.
  "Mrs. Thayer, Mrs. Widener, Mrs. Astor, and Miss Eustis were the only others I knew in our boat."
    "The deck we left was only about 20 feet from the sea."
    "Then we turned to pick up some of those in the water. Some of the women protested, but others persisted, and we dragged in six or seven men; the men we rescued were principally stokers, stewards, sailors, etc., and were so chilled and frozen already they could hardly move. Two of them died in the stern later and many were raving and moaning and delirious most of the time.

Archibald Gracie's The Truth About the Titanic lists all four women as being occupants of boat #4.