This is the part where you can prove you care about her as a friend first and not just as a possible girlfriend. She’s going to be sad, her dad being dead is not going to change and it will take time for her to go through the stages of grief. If a guy were to approach me at a time like this I wouldn’t respond well. Be prepared to wait several more months if not more. If she were to tell you she wasn’t interested romantically would you drop it and continue supporting her or drop her?
You can’t really set a timer on things like that. If you care about her then there for her & wait to make a romantic move until she has emotionally recovered. Her dad is all she can think about right now guaranteed. You know this but her life isn’t about you so just hold your horses until she’s back to her old self
it will be hard. when my best friend died dudes were all over me, i guess cause i was sad. don’t do that. be respectful of her time, help her through it like you would help any friend, but maybe don’t ask her out and don’t expect anything from her for a while. maybe about 8 months to two years, depending on how she handles grief