Hello syed hussain,
Pl be fair in handling your employees.
Are the salary Hikes being given for the ACTUAL performance UPTO April or for the ANTICIPATED performance FROM April? I am sure I don't need to answer that--since you know it.
A Technical Head may be more concerned with the PRESENT performance/response of an employee. But, as HR, you need to more concerned with BOTH the Present & Future. Let the employee go in a happy frame of mind.
Also, the fact that you posted this thread makes me to presume that you DO WANT HER TO REJOIN--pl correct me if wrong [whether she actually does or not is a different issue].
Another way of looking @ the situation is from the employee's perspective: you aren't sure if she will join back--which means that she MIGHT ALSO REJOIN. Given the human mental mindset, IF YOU WERE HER, if & when you are in 2 minds whether to rejoin this company or join another company, would you rejoin if you are left-out of the salary review process--even if you like the company in all other ways?
Another angle to this issue: I am sure you know that such actions in a company never remain a secret. The employees who are still present & would continue to work would definitely know about what transpired--and more importantly WHY. What's the unsaid message that you--as HR--wish to send to them? Hope you get the point I am making.
Hope you have the answer to your query by now--at least my take on it.
All the Best.
Rgds,
TS