Swati,
(In a number of her serials she has shown the wife/husband adopting the illegitimate child (tulsi-karan), in KTH Mr bajaj accepted sneha and prem, in KTH sujal spent a night with charu)
My belief in JW's innocence comes from the Sujal-Jharu episode, if you remember Sujal was framed there, he didn't do anything. Prem was conceived out of wedlock but Prerna wasn't married to either Anurag or Mr. Bajaj at the time it happened. Mihir-Mandira was the only genuine illict liason which resulted in a child out of wedlock.
Rgds,
Pri