Poor Mabel - she really doesn;t have to wear black. I know Friso is in a twilight state but he isn't dead and although the time will come when she does need to do this, but now no-one should crticize her if she wanted to wear something else to an event that obviously wasn't a memorial service.
I agree totally, but maybe it's Mabel's mood which causes her to want to wear black. I'll feel better when I see her in something brighter and looking a little happier, but the grieving process is long and slow.