Well, for one thing, she calls it "Easter", knowing full well that the term is a riff off Ostara, the pagan celebration of harvest fertility. She's not going to be calling it Resurrection Sunday, because she's not buying it.
She goes through her usual Sunday routine. Many of the first morning details are too personal, but eventually the floor is swept, the breakfast dishes are washed, and the pets are tended to. If she had children eggs would be hidden before they got moving, odds are by her husband, before he went to work at dawn.
She bids a Happy Easter to all her friends on the web, and updates her blog.
About 2 o'clock she'll put out the decorations. Earlier than that and you're tempting fate and the cats far too much. Around about 3 she'll put the ham in, wash the potatoes for boiling, and cut up the salad. Around 4:30 her Mother will come over, bearing rolls and asparagus and artichoke dip. They will sit down with tea and call all the assorted other relatives, who are all Catholic, and bid them all a Happy Easter. When her husband gets home at 6:30 dinner will be waiting.
Best odds has her Mother going home before 8, when she will settle with her husband and her knitting.
Now, why, you may ask, is an atheist doing anything special on this particular day?
Because...she wants to.
Simple as that.
Happy Easter everyone.