I think if you choose to serve wine for a brunch or shower then a Rosé is a perfect selection for these occasions - it has the refreshing crispness of a white wine, as well as the medium body of a dry red wine. A pinot grigio or pinot gris is another great option.
If you are looking for a new, unique cocktail specifically for the brunch try a sparkling combination of white wine and chambord in the form of a chambord spritzer.
Mimosa's are a classic brunch cocktail and you really can never go wrong with this one.
Turn your event into a highly social scene, where the conversation centers around trendy jelly bean blends, inspired by classic cocktail concoctions. No alcohol here, but plenty of fresh, tangy flavors. These are a truly unique and stylish favor for your brunch (or wedding receptions, birthday parties or showers).