I'm so glad you were able to confirm that these are your ancestors! It's so nice to be able to get through those brick walls! wasn't there someone who posted earlier in this thread who was also a descendant of William Matthews? I guess you are related!
Did the divorce papers mention anything about the children?
I did go to the library in Lake Forest and I looked at the "Lake Forester" for the last 3-4 monthsnof 1919 to see if there was anything aboutyou father's birth. There were a lot of inane items like " so and so closed their house for the summer and are residing in blah blah for the next month.". But there were very few birth announcements or engagements mentioned in general and I didn't see anything about the Matthews family.
If you send me your e-mail address, I can send you the pictures of the will.