Validity of the counter claim against co-defendants

Question is regarding the validity of counter claim.

Brief facts:  

1. Plaintiff filed a case to claim separate partition and possession from her joint family property of her father who died in 1998. 
2. One of the Defendant has filed a counter claim through the WS seeking separate claim for her share. 
3. She has silently filed the WS behind the back of the defendants. It was never brought to the notice of the court and she has never pressed upon the I.A in two years after filing the WS by way of counter claim.  
4. I have filed an I.A under order 7 rule 11 to dismiss the case since father was not alive as on 2005.  
5. Finally, plaint was dismissed by the lower court since it was barred by the law. Daughter can only seek claim if father is alive as on 2005.
6. It was also admitted in the plaint that the property was sold to third party through a sale deed (also party to the case) illegally behind the back of the plaintiff in 2006. which means as of now property belongs to the third party.
7. Along with plaintiff this defendant has also filed the objection to the I.A stating that this defendant has filed a counter claim which must be considered however, court has not considered it in its order and dismissed the palint.     

Now this defendant has filed a RFA in high court for this counter claim saying that the lower court has not consider her counter claim.  

Now High Court has issued the notice.  

If counterclaim has to be taken into account, it is is against the possession of the property of co-defendant. There is nothing against the plaintiff whereas it should be against the plaintiff.

Can it be valid in law since it is only the plaintiff who can reply to the counter claim. It is only the plaintiff who has been given a right to file reply to the counter claim under rule 6A-G. Even Court can also pass a judgment against the plaintiff not against the possession of the property of co-defendant.

Court in this case has put me in an unlawful situation by issuing the notice to me where I can’t even file a written statement to peruse this case as per law.  

How do I proceed? Will it be a valid counter claim?

I really appreciate if some one can reply to this question.