No its about him being a phone telemarketer and talking to a girl (whom he didn't know was in hs at the time). A "blower" is an old Brit term for phone.
So when he went to find this mystery woman he saw a teenager hence "The Blower's Daughter". The girl I spoke to on the phones daughter. He was a telemarketer who fell for the voice of a girl who's age he was unaware. It isn't about sex or anything sexual. Just embarrassed for the love he thought he had possessed for this Child.