Can I share my 7Mind subscription via family sharing?

Unfortunately not. Family sharing from Apple and Google only applies to the free content of the 7Mind app, but not to in-app purchases, i.e. subscriptions.

On this Apple help page, you can read about what is covered by Apple Family Sharing and what is not. 7Mind is not a participating app.

On this Google help page, you can find out what content can be shared via the Google Play Family Library. In-app purchases cannot be shared with family members.

You can of course use your 7Mind subscription on several devices at the same time, but only with the same profile.