Can i swap memory modules between mac
No, this will not work. Only the RAM for the MacBook Pro and Mac Mini are compatible, as MacBook Airs have their RAM soldered to the logic board.

While you will be able to move the MacBook Pro memory to the Mac Mini, the speed would be slower. Because the RAM is soldered to the logic board of the MacBook Air, this memory can't be moved at all, so you'd still be short new memory.

If you want to upgrade your memory in both the Mac Mini and the MacBook Pro, move the sticks from the MBP to the Mini, then buy new ones for the MacBook Pro. If you just want the upgrade in the Mini, buy new sticks for the Mini's specs.