I am the great grandson of Ida Phillips who is Ada Phillips DeHaven Ross' twin sister. I unfortunately don't have much information on Ada's line either. I think that you have as much, or more, than I do. I have information on the two daughters of Ada and Mr. DeHaven. If you would like that just let me know. My e-mail will be changing here this week as we are moving back to Oregon. I look for your posting here if I don't hear from you this week by e-mail.
Good luck, Mike