Oh I'm so sorry to hear of your loss :( My oldest child is that age right now, I cannot imagine how devastating it must have been for you and your wife to go through I think you may be right that the resurrection hope is keeping her in her faith. It is a way of coping with loss but it doesn't deal with the grief in a complete sense. It just 'puts it off' until the hope is fulfilled (resurrection).
I have had more than one miscarriage, before the 'new light' came about in May this year (where miscarried babies may be resurrected). So when I suffered my losses, I should have grieved properly, yet I wasn't able to (won't go into it now). A part of me died when I lost my babies. Nothing ever prepares us for death and loss, even if it's expected (such as in cases of long illness etc).
Have you tried talking to your wife about it? Or has too much time passed? You might broach the subject with her, to get a feel for how she's thinking.
Once again, so sorry for your loss.