For me it would depend on how they show it.
If they want to send a strong message then Mauli shouldn't forgive. But in real life in many cases people do forgive. Sometimes for familys sake and sometimes for financial dependency or other compulsions. What would it take for a woman of limited/no compulsion like Mauli to forgive. Kunals mom will support any decision she takes, no kids, financially independent. The only factor is dida who can be convinced and will side by Mauli if push comes to shove.
So in the end it falls to Mauli as an individual.
Her world view, her principles and the depth of her emotional dependency/attachment/love for Kunal. She took her vows very seriously and invested her all in this marriage as shown in the flashback. She might decide that marriage is a sacred thing which can't be easily broken and deserves an attempt to be saved.
Some do believe in the concept of redemption, and in peoples capacity to reform. Once a cheater always a cheater adage doesn't always hold true. Boney never cheated on sridevi and there are instances in real life too where people when forgiven are then good for life.
Here though its not applicable for Kunal (yet). He hasn't done or said anything till now that would show he wants Mauli. And Mauli or any self respecting woman should most definitely NOT take the first step towards reconciliation. Frankly he doesn't deserve forgiveness. He is still so fickle in his mind that he can't be trusted. Where he should be groveling over and over again in front of Mauli hes still easily staying Nandini's place.
It is such a personal choice that I might not be able to forgive but I wouldn't look down or judge people who do. I wouldn't call them weak/pushover/doormat.