Was she inspiring her to commit adultery, or to find love, and then end her marriage with Leo? We have no idea of the marriage laws in that kingdom but divorce or anullment is actually a concept that predates feudal times so who knows what they would have written in terms of that (already anachronistic) imaginary kingdom.
I hope the idea was that with incentive to walk away from power that Regina would choose love. Like her mother, she chose power but unlike her mother, it came more from fear of being hurt again than bloodlust to see others suffer. At least, at first.
“If I had a world of my own, everything would be nonsense. Nothing would be what it is, because everything would be what it isn't. And contrary wise, what is, it wouldn't be. And what it wouldn't be, it would. You see?” -- Lewis Carroll, Alice's Adventures in Wonderland & Through the Looking-Glass