Heidi

Hi all,

  I was wondering if anyone could tell me a little bit about the sequels to Heidi.  Our family read Heidi recently and we all loved it so much!  I noticed that the other books are not listed in the module 2 literature along with Heidi.  Is there a reason for this?  Are they not as good?  My kids are 8,6,and 4 if that makes a difference.  Thanks for any help!