Don't overlook the birthday, it's the single most important occasion to a person, typically. Don't overdo, either. A card with a simple sentiment, nothing romantic, is sufficient. Come to think of it, nothing more than your signature is sufficient enough. Keep in mind she's not receptive right now to romantic overtures from you, likely nor will sweeping grand gestures have much significance right now, in fact, it could have the reverse effect with her thinking "Oh sure! He acts like this now..." Just letting her know you've thought of her, by way of a simple card, is enough.
