I think this discussion is meaningless. I mean, u are just 'assuming' that Prerna isn't giving prem her love right now, which is an incorrect assumption.
PREM is sm1 prerna will always always love because he is the symbol of her passionate eternal affair with anurag.
If u observe her dialogues of these days properly, she is blaming komolika for whatever happened to the bajajs. She is saying stuff like "tumne mere bete ko apne saath kar liya" and even sam told prem "komolika will dump u soon and then ur parents will be there for u". So Prerna's fight is against komolika. And mainly, this fight isn't for bajaj's business or his own kids' rights (bajaj and his kids are grown up ppl and they can look after themselves). but this fight is between Prerna and Komolika, FOR PREM. Prerna is fighting komolika the same way she is fighting aparna- to have prem back! besides, prerna has this concept in her mind that prem is doing wrong things because of aparna-komolika, it isn't his own fault. and she LIVES by this philosophy. so we'll soon see her showering prem with love, but to love him, she needs to get rid of komo first, and that's what she is upto these days. She is fighting this battle not out of her love for bajaj family, but out of her desperation to have prem back-free from the clutches of komolika. the mother who touches her child's feet..can actually go to any extent for him.
For prerna, anu-sneha-prem are three ppl that MATTER, and as long as these 3 don't clash in between each other, she can continue loving them. That is why u see prem still showing affection for sneha, and prem not troubling the basus though he has ruined the bajajs. As long as prem-sneha-anu are all on one side, prerna's love will flow for all three of them. her real kasauti will be if she has to choose bet. prem and sneha, or prem and anurag, but that hasn't happened at least so far.
The bajajs really don't matter- they are too insignifant in prerna's life, in comparison to prem's importance in her life. u wud never see her doing a tulsi or mother india- her love for prem overrides everything for her -even her sense of right and wrong, of justice and injustice and even makes her forget that as a mother, she is supposed to love anurag's kids and bajaj's kids EQUALLY.