This is one of the popular books about Betsy by Carolyn Haywood. There are cute pen illustrations by the author.
From the back of the book:
Join Betsy and her sister Star for the best of their Christmas adventures.
Star was born on Christmas Eve, so Christmas is twice as special for the whole family. Star will always remember the Christmas she received a special birthday tree. Another Christmas adventure finds Betsy and her friends on a sleigh ride, with a mysterious driver who claims to be Santa Claus's twin brother. And who could forget how Betsy kept everyone cheerful during a Christmas blizzard? There's a Santa Claus parade, holiday presents, and Christmas carols for everyone!