Sudha is fiesty, forwardthinking, couragerous and and yet traditional in the way she respects her marriage to Ramdhari by not remarrying or even think about another man during those 20 years.
Ramdhari is someone who lives by the rules and lives for another people. He has and will always follow the rules and demands set by the village people even to the extend of giving up his own happiness and love.
Meera has inherited both those traits from her parents - she is feisty and courageous whenever she deals with the pitfalls life throws at her - be it Prithvi or Lakhan or the village people (like Sudha). She has agreed to follow the village demands and have married Prithvi just to save her father's and her mother's honour and in some extend saved their lives as well. She has given up her happiness and love which she had with Akash (just like her father) and has instead married her "mortal" enemy.
Meera is exactly like her parents when it comes to love and respecting the marriage vows as well. Sudha pined for Ramdhari and never remarried and respected the sanctuary that is called marriage. Meera will be doing the same thing when it comes to choose between Prithvi and Akash - Meera when given the choice will be pulled back to Prithvi by the Mangalsutra whenever she even thinks about Akash.
So to summon up - Meera might have married Prithvi for her parent's sake but will either stay and try and get along with Prithvi or she will separate and pine for him ie 50 percent Sudha 50 percent Ramdhari.