Examination of the will of her brother John shows that she was not his heir; she may not even have been alive at that time.  He did, however, leave £20 apiece to the children of his hephew, almost certainly her son, Thomas.

Further John had a late brother Richard who had two daughters, one with several children and to all of them he left substantial sums.  I am not sure who was John’s heir, but the residue of his esate definitely went to the children of his friend John Andrews.

So, October 2016, Margaret has had ‘heir’ dropped from her details.
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The site of Ivan Thomas Cary Elwes says that

“Margaret Powell married Thomas Powys of Berwick House April 28, 1703 in St. Julian, Shrewsbury, Salop, England”

But Thmas was probably born soon after 1603, the latest year in which his parents married, so it would hardly be likely that he was marrying anyone as late as 1703.

However the actual marriage on that day was between Thomas Powys Draper and Bridget Baldwyn.  A copy of the Register page has been obtained and the above site needs some correction.
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