One way to keep her happy and make her feel special is find out what she has been wanting to do and make a day of it. Maybe it is a night on the town, maybe take out at home.
Wash the dishs. Do something she has been bugging you to do around the house.
Maybe a spa gift card for a day of pampering!
Show her you love her! Give her a kiss like you really mean it, wait for the right time. Timing is everything!
Flowers or a random gift you know she will like. Let her know you thought of her.
Give her the gift of some alone time. If you have a baby she could really use some time to catch up on her reading, watch a movie she wants to watch, go out with the girls, who knows, but she deserves some time to herself too.