Something is peculiar about the children of John & Margaret. Many of the estates ended up with distant relatives, putting into question whether they had children or not. For example Tillington was passed to this John from another distant cousin John d. 18 Feb 1395/6, yet that John appeared to have a daughter Elizabeth, as well as a Kathleen. Similarly estates were passed from this John to distant male heirs. One person suggested that the estates in question may have been entailed to male heirs only, thus not being able to be passed through a daughter.
I have not seen a conclusion to the mystery.