I think I'm alone here, because I can understsand why the OP is miffed, knowing that of the three people in her home, she will be the one doing almost everything that does have to be done, however little that is, thanks to her DD.
In reality, I doubt of has much to do with it being Christmas - probably just a build-up of underlying resentment towards two people who would seem to take her for granted. She may be the 'fittest', but that shouldn't mean that they take the p* and spend the day sitting on their @***s!
It might seem very minor in the scheme of things, but even small things can slowly eat away at you.
Blimey, there are loads of threads where people moan like mad about the most trivial of things. Cut her some slack!