If you look at kibana-version/installedPlugins/marvel/package.json what is listed in name and version? Something like this:
"name": "marvel",
"version": "2.1.1",
"repository": {
"type": "git",
"url": "http://github.com/elasticsearch/elasticsearch-marvel.git"
}
I would check the elasticsearch log files to see if the marvel agent is having any issue collecting or storing this data.