No bias at all :)
Disclaimer : all the opinions are my own based on what I have watched the last couple of months.
In the beginning of the leap, she was portrayed as the second Archana who was strong , loving and had a golden heart. Her character has been persistent all along except for her misplacement of priorities.
Arjun confesses his love for Purvi, Purvi is reluctant.
She stops him when he is leaving at the airport , well an instinct stops Arjun.
They share their feelings to each other, all is well.
Purvi was unaware of his promise to Marry Ovi.
By then even Arjun forgot his promise (so much for childhood friendship)
When Purvi comes to know he is engaged to her "sister", she is hurt.
She glances at Ovi and Arjun , can't help feeling jealous.
Arjun reassures her it's her he loves, he will tell Everyone he loves her.
He finally does and the two reunite.
Of course , Archana wasn't going to accept a son in law who cheated her other daughter so she puts forth a condition to give up his luxurious life.
Purvi sees Arjun struggle , working as a mechanic and he final fulfills Archana's condition of handing 10 thousand rupees of his own income.
Then everyone is happy, Purvi and Arjun are happy.
In the midst of their engagement and wedding .. Arjun takes a bullet for her.
Purvi does know Ovi loves Arjun a lot but if she doesn't accept Arjun she would be ruining 3 lives , while she hoped Ovi would soon recover from this heartbreak.
When Ovi puts the deal forward , she accepted it for her mother. Her happiness was really because of her mom reuniting with her long lost family.
When she found out she was pregnant , she left . She didn't want to disrupt Arjun and ovi's marriage.
She figured they would work it out.
But destiny played yet another cruel game, Ovi's pregnancy had to be dealt by Dr. onir who proposed to her because he liked her. When he found our she was pregnant , he told her it would be hard to live here alone as a single mother.
Purvi and Arjun come face to face once again but she is determined to make his and ovi's marriage work.
Hence she goes through anything to bring Ovi to the right part (e.g quit alcohol, love the baby)
Finally Ovi makes peace with the past, and befriends Purvi
They now became "sisters"
When Ovi loses her child , she thought that way Ovi would not be depressed about her stillborn while Pari would be with be with her biological father hence she swaps the babies.
The yearning for the baby was a natural instinct on a mother's part.
When the truth reveals, she is ashamed but her and onir has sticked to one thing ; they did it for everyone's betterment.
Onir lost his license , Purvi feels responsible.
Purvi never meant harm. She did make mistakes , a lot of them but she always thought everything would work out.
I know we don't particularly like her actions but if we look at it from her perspective she did nothing wrong.
She did not want to hurt anyone hence she did all this.
My opinion : (personal) about time she minds her own business