Although Bhaskar, Vasant, and Avinash have covered most of the points and they are absolutely right, I would just like to add a pointer: An employee is dependent on his/her job and salary remuneration to maintain his/her life. Thus, unless he/she is absolutely casual or doesn't care about money (which is rare), there will always be a genuine reason behind their consistent late coming.
So even if you wish to terminate her, please make the process a non-painful one by counseling him/her and explaining the reasons for termination in detail. Do not just say, "What to do! The Management has asked me to terminate." As an HR professional, you need to take responsibility for termination.
And if you feel he/she can improve, then convince the Management to give him/her just a warning letter with an observation period of 30-60 days. That way, at least you will be guilt-free, as terminating an employee can be very stressful for an HR.
All The Best.
Regards,
Dr. Mazhar Khan GM - Human Resource.