Coventina & Gaja Lakshmi
In Coventina, we have a river deity or nymph that is primarily worshiped in Northumberland. This would likely point to the origin being a mortal deity. This is common with the deities who are associated with rivers, food, gardens or the hearth.
While I have not yet found a representation of goddess with the same lower-half voluptuousness as the Gaja Lakshmi, there is some similarity between her figure and that of Coventina. And the Gaja Lakshmi figure most resembles that of the moodevi or Lakshmi Devi/Jyestha Devi.
Of note is that there seem to be competing goddesses even in these examples. Jyestha Devi is the “older” sister of Lakshmi. And there is another water goddess competing near the same area as Coventina named Sequanae