Albums, as in music songs are DRM free. Meaning that you can copy/add/play them from any device you want. There is no restriction on how many devices the songs can be played and the devices playing the songs do not need to be activated with your Apple ID. The restrictions previously mentioned only come into place for movies, not for music. But keep in mind, that the songs are watermarked and the account the songs were purchased with appears as the owner. So yes, you can share the music freely and legally within your family.