they basically used the dna from both girls to somehow fertilize one of the other girls eggs with no sperm it is called science which is getting closer and closer to being able to actually make things like 2 women having a child together possible
With current technology it is possible to create eggs from men's skin cells it just doesn't work the other way right now (for 2 women)
some genetics labs are working on how to turn a womans cells into basically sperm so 2 women could have a child together
Did she get a sperm donation or something or did they do some sort of method they developed?