Yep! ;-) I was thinking of having a base station or repeater at my house!
Here it is straight of the FCC Website: "(a) Except for a GMRS system licensed to a non-individual, one or more small base stations or a small control station may be added to a GMRS system at any point where radio services are regulated by the FCC"
Therefor, it seems to me that I could have one or more base stations. One at each house for example.
Also, "a) An individual GMRS system licensee may permit immediate family members to be station operators in his or her GMRS system. Immediate family members are the:
(1) Licensee;
(2) Licensee's spouse;
(3) Licensee's children, grandchildren, stepchildren;
(4) Licensee's parents, grandparents, stepparents;
(5) Licensee's brothers, sisters;
(6) Licensee's aunts, uncles, nieces, nephews; and
(7) Licensee's in-laws."
This goes on to say that any of the above, including Grandparents could operate a GMRS station in my GMRS System. So, If I outfit each house with a unit, there is no reason why they couldn't use it. According to the FCC, I believe that I am correct.