Evedentiary value

Sir,

  I am an Inspector of kolkata police,I would like to share that on 2.11.14 an incident of robbery occurred in my police station area where the miscreants assaulted a 75 years old lady at the point of dagger  and took some cash & fled away with booty.The old lady informed her daughters over phone who came and found her mother been robbed of at late night hours.

Now my question is , can these two daughters who have heard the entire incident from her mother's mouth can be cited as witnesses,if yes then what type of evidence they can tender?will they be considered as hearsay witness?They are not eye witnesses, then what type of evidence can they testify?will that evidence consists of  good evidentiary value?Any help or light please.

Thanks and regards.

                                                                                                                                       Inspector P.Mukherjee/SHO