Mary Bray (Crowell) - Spouse

I just completed a merge, perhaps improperly, on Mary Bray, listed as my 8th GGM. The two Mary profiles I merged had the same birth and death dates, same name, same parents. Should have been a no brainer, but we had two different spouses (not uncommon). After the merge, I further reviewed the birth dates of the children and the marriage dates, which present what appears to be an overlap - red flag that something is wrong.

We have Thomas Bray married on September 24, 1723, with children ranging from 1725 through 1750.
We have William W Fullerton married on December 30, 1725, with children raging from 1731 through 1734.

Sometimes Mary is listed as Mercy. Might we have two siblings, one that married William and another Thomas? If so, what is the birth date of the other and which is which. Or do we have a completely different Mary Crowell that married one of these men, who belongs to different parents. I haven't had time to fully investigate this, so I wanted to bring it up for discussion so we can take whatever actions necessary to avoid future problems.