It has so many pitfalls. There's a real "Where do you go from there?" issue too, which is hard to resolve- either it is a reset switch, which has been greatly overused in Who, or you have to carry on with the 'Daughter out of nowhere' idea and... I dunno, I don't quite see that going anywhere greatly involving.
And yes, then you have all the fuss about how she has come about, which could be equally awful.