Arushi could never be paired up with Tunna or Chandu in the first place... so both of them were always safe from her.
There is a very strong tendency in most serials to show that a girl (however poor or however rich she may be, howvever educated or uneducated she may be) she always marries into an extremely rich family, who pretty much eat gold for dinner and sleep on a mattress of currency.Unlike real life, the hero for the girl, will never consider the fact that the girl he is about to marry may have already had multiple failed marriages, may have a kid or two, and may even have married his own brother/best friend in the past. He will also ignore the fact that his mother hates the girl, his cousin has eveil intentions for her, and that he himself already has a girlfriend who will come back soon for revenge.I know the above points are not all related to Arushi, but that is generally what happens in such serials. Therefore, Arushi's future is set. Despite her malicious past, she is all set for a rocking future.