I'm confused. You said you saw the screen were she was standing in front of her house after you peeked through the window and got rid of the old man. You say that the hint says you must have quality time with Dee Dee and that means talking with her in front of house, going to Carlos, going to the fountain and make it run and then practice with her.
Could you upload a savegameXX.dat so I can see exactly at which point you are? Because you describe things that suggest a point in the game, but then says it isn't there. So I'm really confused right now
Added:
This is conflicting so you did things out of order. When you bring Claudia to Jeb Village the hint suggest to explore it. That hint is finished when the old man leaves to the cafe and you get the transition scene were Dee Dee wonders who the handsome stranger is. At that point the hint suggest that Willy has other things to do, so you don't need to speak with Dee Dee yet...
After other hints there will be a hint that says Willy needs quality time with Dee Dee. At that point you go to the house were you peeked and she is standing in front of it, just like the above transition scene showed. Talk with her andto the point were Willy promise to talk to Carlos about her. Do that. Carlos asks Willy a favor and see how good Dee Dee is. Go to her. At the end she says she can't practice because of Mr. Goat -- the old man reading by the fountain. Willy needs to repair the fountain (see walkthrough). Then you've the quality time the hint suggests...