The Life of Faith books often tend to be a little unrealistically spiritual, but I enjoy them anyways. Not to say that people shouldn't live out there life totally for the Lord- they ABSOLUTELY should! But the way it is presented in the book makes it seem a little unrealistic to live that lifestyle, when what books like this should be doing is showing how it's possible.
That said - I've been enjoying this series. They are not Catholic, but they are Christian and I haven't run into any flagrant anti-Catholic issues. The first book is very depressing. It just is. It's fast paced, though, so you'll want to read to the end.
These books were much better than the first 3 Elsie Dinsmore books I read (from the same series). The first part of Elsie's life was SO SO SO SO SO sad that I got depressed every time I read the books and it felt pointless, even though she was living white martyrdom beautifully. Violet, on the other had, is less depressing and a little more interesting. If you've read about Millie Keith and Elsie Dinsmore, you'll enjoy these books because Violet is Elsie's daughter. There are so many references to the Stanhope family tree and (spoiler:) you get to meet Cyril's son! :D