the big question here is whether your mother is actually a narcissist, or 'just a run-of-the-mill-unreasonable' mother. if a genuine narcissist, then it's irrelevant what you try to plan for the rest of the day - her goal will be to ruin your birthday, and she will achieve it!
my suggestion?
• you arrange a special outing/romantic overnight stay, BEFORE your birthday, if at all possible. then you can say, if appropriate, 'oh, we already celebrated.'
• you start watching some you tube 'seminars' about narcissist mother's, and learn how to deal with this problem
• you make a pact with your husband that no matter what you will not allow your mother to come between you.
• and finally, don't be put off by people who think they know better, but actually don't understand. narcissism is a thoroughly misunderstood problem to deal with, even by experts.
good luck - this may be tough, but you'll get a new life.