Syngonium, if that's what you have, grow naturally in the shade of large canopy trees. For example, here in central Florida they are used as ground cover under trees where grass or other landscaping might get choked out by shade and roots.
They prefer dappled sun light and might be content with what your prayer plant gets, thought it might need a little bit more light. Once syngonium take off they are prolific growers and many people don't realize they're a vining and climbing plant.
I suppose try giving it a little more light and maybe worry about separating the two if you feel it necessary. Maybe if you can get it growing the leaves will take on more definition and we can see what it really winds up being.