I'm so sorry you've been through such a terrible time.
If your daughter's around before Christmas, go up late one night to the nearest big town to look round the Christmas decorations and have a cocktail in one of the bars. Make some Christmas decorations together. Binge watch some Christmas films wearing Christmas hats and eating minced pies and drinking sherry. Wrap presents together.
See if you can volunteer to help together for Crisis or other charity on one of the days, dishing up food or washing up. Get up on Christmas morning and go for a long walk in the park. Our one always has lots of people in and people dressed as Father Christmas and dogs dressed as crackers etc, which is rather cheery.
Do you have any friends living nearby with older children? If so, maybe invite them round for drinks in the evening and to play games - cards, Articulate or something like that.
I'm sure that other people will probably have lots of better ideas, but there is some to get you started.
Meanwhile from the experience of someone close to me, the trauma for her about the not being believed (ie him being found not guilty) is almost worse than the rape. It's like being gaslighted and your trauma not acknowledged. If she is willing to talk about it with you, I'd ask about that and really, really listen, don't reframe it in a more positive way, just acknowledge how it is for her. Also see if you can get some counselling for yourself. You may have some unprocessed trauma. Mind may offer some low cost counselling in your area.
Is she not estranged from her sister/gran/dad? If so, could you encourage them to meet up. She may not want to do that out of loyalty to you, but it maybe just what she needs to be supported by all the family.