Reverse Merges - Mary MERCER

I have reversed this merge https://www.geni.com/merge/view?revision_id=79092105990 which merged

Mary Berriman
* husband John Berriman
children
* 1760 Joseph Wheeler Berriman
* Hannah Berriman
* Mary Berriman
* John Berriman
* William Berriman
* Rose Berriman
* Ann Berriman
* Thomas Berriman

with Mary Pennell
* born 1689
* died 1768
* married 1710 to William Pennell 1681-1757
Children
* 1712 Thomas Pennell
* 1714 Hannah Halcombe / Ellis
* 1717 James Pennell, Sr.
* 1719 Phoebe Lewis
* 1721 Ann Edge / Worrall
* 1723 Robert Pennell
* 1725 William Mercer Pennell, Jr.
* 1726 Samuel Pennell

These could not be the same person - if born in 1689 she would have been 71 when some of her children were born.