Technically, the "family rule" applies to AC members, not Emerald/Sapphire members flying internationally, so you are technically allowed only one guest.
In actuality, the AC may allow your family to enter with you, particularly in the US. The odds of this happening at ACs outside of the US are a bit less, but not impossible.
Rules at non-AA oneworld lounges are typically vigorously enforced, so expect to be refused at these clubs on most occasions.
The lounge access policy is on the AC site:
http://www.aa.com/aa/i18nForward.do?...ungeAccess.jsp