Why would Naveen harm Vinu or Sharma family right now ? What will he gain out of all this ? Vasu is separated from her sons and by putting Vinu behind the bars she can take her revenge against Sharma family. She holds them responsible for her miseries.
Life is always not that straight forward nor the people Anu. That's reality. Have you heard the story about about 2 cats and a monkey> The two cats were fighting over a loaf of bread and the monke took advantage of both the cats in the name of helping them to split the loaf in 2 halves... pretending to make two exact halves, the monkey ate the whole loaf..
That's exactly what is happening in RV parivaar... You are only seeing ulterior things and not behind the scene scenarios. NAveen-Avni are the ones who will benefit by keeping the mother-sons apart. So, my guess, Anand must also have joined hands with NA.