It’s not clear from your post whether your daughter is looking for a Christmas Dinner or just a dinner on Christmas Day.
By Christmas Dinner I mean the full traditional turkey and all the trimmings. This tends to be eaten sometime between lunchtime and mid-afternoon (like a Sunday roast). There will be some pubs and restaurants open on Christmas Day but they will tend to be offering an expensive pre-booked set meal, and often only earlier on the day and closing for the evening.
If what she’s looking for is merely somewhere to eat dinner on Christmas Day - that is, in the evening, I’d imagine Chinatown or other enclaves of ethnic restaurants might be the best bet.
As has been said, there is no public transport that day. Perhaps you could give us a sense of what sort of meal your daughter is hoping for?