If your Wife is in a show, it is expected that you should attend at least one of her performances. Several, if you want to earn brownie points.
Also, as a token of your love, affection, and the phenomenal job she has done, it is expected that you send/bring flowers to her for at least one of her performances. If you don't know where to start: An arrangement in a vase delivered to her dressing room on opening night, or an arm bouquet personally delivered after the show on closing night are both stellar options. ***It is important to note that the flowers should be presented to her at the performance venue, when friends and adoring fans are still present... flowers waiting at home do not have nearly the same effect to make your special lady feel even more special and celebrated as she deserves to be for her hard work.***
Be sure to include a note telling her you love her, you are proud of her, she did a fantastic job (or if delivered pre-show... "Break a leg" not "good luck").
Hope this helps shed some light on the situation! Feel free to share and distribute this info as you see fit.
***Please don't think I am a greedy and/or presumptuous person for saying such things... I have quickly discovered in my own marriage that it is better to state your expectations clearly for your significant other than to just HOPE they know what you expect... usually the latter method ends in disappointment and frustration for both parties.