As long as different skills afre covered and she is engaged in her learning I wouldn't worry. They need to keep it interesting though. Is it an overall topic or something like science? Some things are revisited.
MMmm it's the keeping it interesting bit i'm worried about. Surely there are enough juicy subjects in this world to learn about a fresh than to have to go over old ground? I can't help feeling disappointed.
Dd's school has a 2 year rolling plan so she now in Yr4 she is covering a topic that she last did in Yr2.
However, even though it is the same topic she is covering different aspects and skills within the topic.
I think you will find that your dd will be doing different topics within the main topic e.g. my dd is doing Fire this term in Yr2 she did The Great Fire of London and Samual Pepys this year she's doing volcanoes and the romans.