Sister of the Bride by Beverly Cleary

Barbara can hardly believe her older sister is getting married. With all the excitement of wedding plans going on, Barbara can't help dreaming of the day she will be the bride. She can't wait to fall in love.

But as the big day gets closer, wedding planning often turns into family arguments. Even the bride and groom are bickering over details, and Barbara's fun-loving sister is turning into a very practical, grown-up person. Weddings are fun, but all this serious stuff is scary enough to make Barbara think she's not going to be rushing into a serious romance any time soon.