Salary Increment Extension Due To Maternity Leave

Hello,
I am working in an IT Company. We do salary increments once in a year during their service anniversary time. One of our employees taken 5 months maternity leave , ie 3 months with salary and 2 months LOP. So Should we extend her appraisal period to 3 - 5 months as she was on leave for the period. Is it ethical ? Or to give increment on her service anniversary ? Please let me know the thoughts

In government service one should not be on leave ( other than casual leave) on the date of his increment. So check with your organization's service rules.

Generally date of release of annual increment is also extended equal to the period spent on leave without pay. If the present case is on medical advise, then it should not be extended as it is beyond the control of the employee concerned.

An employee during leave draws leave pay and therefore annual increment if it falls during maternity leave should be given only on her joining duty.

I think your company is doing its appraisal based on performance and days actually worked.
If the employee has dine wrk for the full year, and her appraisal can be done in her absence, then probably it makes sense to give her the increment.
If not, then it is logical that she will get the increment after she resumes work, with appraisal taking place then including her changed ability and focus to work at that point.
The decision will also be dependent on how important it is to retain the employee. If it's is important then it's better not to risk annoying her and just give the increment anyway