I doubt we would have changed the names we gave them, although when we gave DS, the name we gave him we did not realise that, along with Paul and Steven they were the most popular boys names (which we also considered) of their year and period, so had we known that we might have reconsidered.
DD got a family name, plus her paternal grandmothers name - and would always have been so named.
However, I always liked the name Jonquil, not sure why and that would have been in the running had we had two daughters, as it was we had one of each. If DD, our second child, had been a second son, she would have been called Matthew, again a very popular name, although, again, we didn't realise this.