You can get the printout of all the postings which shall be proved in court being primary evidence as per evidence Act being documents. you have no need to worry. The onus in on other party to disprove it.
When attempting to view the Facebook pages of parties and witnesses, however, lawyers are bound by certain ethical restrictions regarding the means by which they attempt to access private information.  Lawyers scouring social media sites looking for evidence sometimes strike gold.
Taking Facebook a social network documents as evidence can be submitted as primary evidence but there is no guarantee that these are published by the owner, the best way is take help of Facebook support team to identify the IP Address of the published message with all the timestamp location.
So the evidence must be properly been analyzed by cyber experts, add justified and certified documents to the Court.
You can preserve particular links for the postings/photos as evidence and simultaneously get assistance from fb through LEA in ascertaining the facts .www.cyberorgindia.com do provide expert evidence gathering services.