Maya didn't do holidays. They always brought back traumatic memories for her. She did her best to hunker down and try to get through them without thinking as much as possible.
This was one time her husband's hatred of sentimentality came in useful. He didn't care about Thanksgiving, Christmas, or New Year's. He didn't even celebrate his own birthday. She had plenty of bad memories associated with birthdays but still celebrated hers to mark the passage of time. That she had survived another year.
He had given her permission to celebrate his this year though and she wasn't going to let him down. Since it would probably fall when they were on the island, she ordered his gift in advance and told Cassandra very sternly to hide the order from him.
"Why do you want me to do that, madam?" the AI asked.
"It's a surprise! I don't want the surprise to be ruined," Maya insisted.