Yes, it was obvious but I thought there would be more "meat" to Nelle's revenge. It seems it is all based on a lie or misunderstanding. Carly didn't actually "do" anything to Nelle directly. To say that this reveal is a disappointment is an understatement.

@Youcanmakeabettermovie said:

...said no one ever. It was obvious Nelle was Frank's daughter when Carly and Bobbie brought out the photo albums and Nelle just about collapsed when she heard Frank's name! Has Frank ever been seen on the show? I know his ex-wife Virginia was on in the 90s until she died. Bringing Frank to town (yes, supposedly he is dead) would be an interesting way to redeem Nelle since apparently she was doing all this for her father (did the writers forget that part?).

Frank was never shown (he was out of the picture long ago when Carly premiered), and having a reanimated corpse show up in town is certainly a viable option on this show.