how does chachi know about shivangi being a naagin?

i haven't watched naagin for a few weeks and today i saw that one of the chachi's, don't remember her name but the one that's not deaf knows shes a naagin. how did she find out and how come she's not telling anyone else? thanks.

She knew whole revenge story...

And her name is nidhi...

Originally posted by: Sweet-devil

She knew whole revenge story...

She has seen shivaangi in naagin form in last week episode.

She knows whole story how shivanya was killed how rudra nd shivangi are planning to take revenge.

She is on their side only now..

She took their side aftr knowing yamini's truth of killing rocky's parents..