Answer:
Yes. However some covens have rules against sharing information with outsiders. I personally think that sharing between fellow practitioners is perfectly fine. Though I don't think it is a good idea to share the names of other witches you know. I myself do not want my name spread around my small town as being a witch. It is not that I am ashamed of being a Pagan but I have had death threats in the past from church goers and it just easier to avoid that. Lol.
Basically if you are sharing only your own information, personal spells, and no one else's information (without their consent) then I don't see anything wrong with sharing with your fellow Wiccans/Pagans/Witches/etc.