I think Garima knows something to do with dadi...

The way Garima acted when she saw dadi was showing that she has seen her before, and when Khushi was telling buaji about Arnavs past she came and slapped khushi with such anger, something is up, but whatever it is... Garima is not Khushi or Payal's biological mother... she is their step mother

Actually she is Khushi's Aunt and Payal's step mother. Khushi's mother was Garima's sister. I actually like her character, because she is played her role as a mother well. She was angry with Khushi after breaking of Payal's marriage but the very next day she did not let her be terrorized by bua. Then when Bua was forcing her to marry Shyam she although her husband was sick was actually even then after bua for forcing Khushi to do something against her will. Then she was angry with her for marrying Arnav but for Pagphere she had a gift brought for Khushi. Today she was upset that Khushi dared to say that Arnav's mother committed suicide which makes me think she knows the whole incident that Arnav's dad made her mother commit suicide and also some other facts. She also smiled when Arnav came for Khushi.

Probably Garima and Anjis mom were best friend and she knows what has happend 😕