I will add some important points:
* How upset is the employee by this loss? If it's someone they knew, but who wasn't part of their daily life, a day or two to attend events may be plenty. They'll be sad, but not wrecked. If they were close, however, they will be extremely upset and need longer. A few days to a week is good. A death in the immediate family is shattering. Do not expect them to function any time soon. Give them at least two weeks, and more may be better.
* How important or risky is the employee's job? If they're a cashier and they start bawling on the job, it's embarrassing but not dangerous. If they're operating heavy equipment, that's a safety hazard. If mistakes on the job can cause significant problems, you really don't want that person back during acute grief, because they won't be able to concentrate fully on the job.
* Give employees input. One size does not fit all. Someone may be estranged from their father but extremely close to an uncle or next-door neighbor. Be alert to disenfranchised grief; a miscarriage can be as shattering as the loss of a four-year-old. Ask the person how upset they are and how much time they need. Hope you can get an honest answer instead of incoherent blubbering. Although if they're crying too hard to talk, you should probably max out the leave. Conversely, some people need to stay busy, because they'll get better faster if they keep moving forward. Let them choose when to come back.
* You can help by assembling a packet of resources for bereaved employees. There are places that print brochures about healthy grieving, complicated grief, and other topics. You can include information about local cemeteries, funeral homes, counseling centers, food delivery services, and so on. These can be helpful to people who might be too overwhelmed to look up stuff that would normally be easy to find.
* Does your workplace have an emotional first aid volunteer? If not, try to set that up before someone dies and you have an employee bawling in the bathroom for half an hour. That's a really awkward time to work out a policy for handling it. Your employee will probably return to functional sooner if someone is there to suggest they take a break before they lose it completely, or offer them a shoulder to cry on when they need it.
* Think about the losses in your life. How competent were you, really? Should you have been doing the stuff you did then? Would you have felt better if you had more time to recover? Did you hurt yourself or someone else, or make other serious mistakes because you were too numb, sleep-deprived, crying too hard to see straight, etc.? These are preventable problems. Death is inevitable, but overburdening the bereaved is not.
America does a piss-poor job of taking care of people. This does a lot of avoidable damage. I wonder how much harm is done by bereaved people trying to meet social demands while mourning. We can do better. So if this is in your power to fix, then fix it.
See also my posts on Coping with Grief and the Grief Questionnaire.