Its been a while since your querie appeared on this site but I hope the following helps.
I do volunteer work at the new Hinkler Hall of Aviation in Bundaberg and Katherine has a story board all of her own in there.
She did indeed marry Bert on 21 May 1932 in Connecticut USA. The marriage was, of course, cut short by Berts untimely death in Jan 1933.
As to whether Katherine knew of Berts long time partner, Nancy Jarvis, a number of stories abound. Most agree that Nancy and Katherine knew each other but on what terms is, to the best if my knowledge, unknown.
The information in the magnificent Hinkler Hall of Aviation has been extensively researched and can be accepted as true in every respect.
If you ever have the opportunity it is well worth the visit, put aside at least 2 hours and be amazed and impressed by this great attraction and the man it celebrates.
But anyway, visit or not, try this link: http://adbonline.anu.edu.au/biogs/A090312b.htm
It is a concise but marvellously complete biography of Berts life including his marriage to Katherine,