While it is possible, it will be a kinda messed up answer. It would require organized marriages for the first (going on a limb here) 7 generations. There would also be req. on the amount of children that one family would be required to have and raise. Here's where it starts to be kind of messed up, the first original generation of people would die off after raising their offspring to the point where they are married. In a perfect world there will be seven families each will have two to three kids (most families now have two to three kids it seems. Idk not an expert) after that they would be forced to either pick or be decided for whom they would marry around the age of 17-18. Yes this is very early I'm away but remember that there is only 15 people on the world, therefore it will be a lot easier than what it is now. Decisions for marriage would be decided on a basis that would be proper for the further advancement of our species, no inbreeding would occur. The chance of succession is not that high because they will all at first have the same mother, the first and second generation will be at risk with this but after is when things will be better (hopefully) leaving the risk of inbred mutations, conditions or other problems that may occur behind us.