Like @Pandora, I don’t know if your grandson’s dad has passed or has just disappeared. Unlike @Pandora, I think it makes a difference. I suspect, though, that he has disappeared, because she seems to be envious of her friend, whose baby daddy is helping bring up the child.
Your daughter is alone, and being a single parent, of course, is a really hard job. Is she getting help anywhere? Does she work? Is she still in school? How do you help her out?
I’m not sure what you mean by “come to grips” with the fact the father of her child is gone. Is she ignoring the baby? Is she acting like she can’t do anything? If this is the case, there is a possibility that she has post-partum depression. Has she had any follow-up appointments with the hospital or midwife or doctor that was caring for her before the birth? If not, she should go in to get checked for depression.
Even if it isn’t post-partum depression, I’ll be it’s depression. You are young, and ill-quipped to care for the child, perhaps uneducated, and your baby’s father is gone. That’s enough to send someone into a serious depression.
I’m making a lot of guesses here, so I may be really off base. You didn’t give us much to go on. My hunch is that you want her to kind of “snap out of it” and start being a responsible mother. She is blaming the lack of a father to help as the excuse for her being unable to do much.
But that’s not really it. It’s not that you can explain to her that the father is gone, and she’s got to get it together to be mom. She knows this. What she doesn’t know is how she can manage it. It seems overwhelming.
I think she needs therapy, and baby raising classes. She needs to be around other real moms, not virtual moms on facebook. She needs to learn, step by step, how it is possible to take care of her baby. I’m guessing she’s still in high school. I don’t know where you live, but many cities have special programs for young women with babies to help them through. You should probably contact people, either at these programs, or at some other young mother support program in your area. The therapist may know of such programs.
There is help. You just have to go find it for her. She won’t find it for herself. She’s too out of it at the moment. Depression is serious. If you can get her to meet with those who can help her, you’ve done your job.
Please forgive me if any or all of these assumptions I’ve been making are wrong or are insulting. I really am trying my best to help. But in the absence of the story, I’m inventing one myself, and I could easily be wrong. Good luck.