A: No. The film ends conclusively. The book has no sequel either.
Maria discovers an ancient feud between her family (the Merryweathers) and the De Noirs (a rival family). According to legend, only a "true Moon Princess" can break the curse by restoring the lost moon pearl and uniting the two families before the next thousand moons (a specific date approaching fast). HDThe Secret of Moonacre
A: Yes – ages 7+. Some mild peril, a scary lion, and a few intense moments, but no gore or strong language. a scary lion
It seems you’re looking for a guide to (often misspelled or prefixed with "HD" for high-definition availability). and a few intense moments