Yep ... we love this book. We read Bartholomew's Passage for advent this past year and were not disappointed. They do follow sequentially so Tabitha's Travels comes next. Then there is one for Easter (Lent?) called Amon's Adventure. Be aware however that Amon is Tabitha & Jotham's son (not a problem to read out of order but it could be a spoiler) and I've read that it is more suitable for a slightly older audience.
Wendy
This story is definitely fiction and would be fantastic for adventure seeking children during Advent as a lead up to Christmas. Designed to be read a chapter a day during advent (including a schedule for how to read the last week which could be any number of days depending on the calendar year), our family read it in one week during January. As you read, you will become completely engaged in the life of Jotham, a poor shepherd boy living at the time and area of Jesus birth. Jotham is too young to completely care for himself and yet old enough to regret his disobedience. We watch the consequences of one night of poor decision lead to his separation from his family and an incredible series of events that include chases, cavern tunnels, jesters, biblical scrolls and about part way through the book we are introduced to real life biblical characters. (I loved it when my kids clued in that it was a biblical person). Each short chapter (approx. 4 one sided pages each) ends with a few paragraphs that are like parent notes for kids to hear. Here is a random excerpt "Learning that there are consequences for our sin is not very pleasant... But them that was exactly why Jesus came to earth..."
Our children were aged 7-12 and all enjoyed it very very much. I would be quite comfortable with any of our kids reading this again on their own. If they didn't know the story, I would recommend approx. 10 or 11+ because of the danger Jotham finds himself in. CAUTION - each fast moving chapter ends with a cliff-hanger - some of which make you wonder if he will be killed by the bad man (who is VERY bad). If you have sensitive or younger children, I would recommend either waiting a few years or do what we did - not read it before bed and have enough time to read a few chapters and as a parent choose to stop at a not scary cliff-hanger.