Can I share Google Keep notes between people? Is there a way to share the notes of Google Keep between different persons? For example, could I link the notes to the todos of Thunderbird Lightning, or can I share the notes between two different Google Accounts?
Currently there is no way to share notes on Keep in the same way that you can share a document.

However, if your goal is to share notes between a fixed amount of persons (e.g. family members,) you can always create a new Google account, add it to all Android phones that you need to share on, and enable sync of Keep only on that account.