as long as the vet says she is healthy, i think she is okay - just smaller than usual!
bree goes through weird growth spurts too. she is 8.5months old and is 2 lbs, 5 oz and has been this weight for at least 6 weeks. she was stuck for the longest time at 1 lb, 9 oz, finally creeped up to 2 lbs and now is "stuck" again. my vet says she is very healthy and that she is probably done growing
being tiny in itself does not necessarily mean health issues. but it does mean you have to be that much more careful and protective of them