How to deal with a using coworker , i have a co woker who has been on long maternity leav 8 month?

she is expecting to go come back to work after 8 month vacation , she is asking for best working hours to work from so early when work is not stated yet and leave so early and she is saying she will not respond d to emergencycy work and will leave at its hour no mater what and asking me to come it its hours. our work include a lot of emergancy and extra hours , she is a close frined of mine and she has helped me before . tell me what to do
I would definatley sit down with her and the boss and write down exacly what each is to do. Otherwise you will probably get the short end of the stick and think she got it easy. I don