Spoilers for the novel and probably the movie
In Stephen King's It, one of the two reasons Bill Denbrough wants to kill It is to gain back his parents' love (the other reason was revenge for George's death).
This leads to the question, is there any clue as to whether they ended up loving him again after the Losers killed It?
Well, did they really kill It? Surely not if they're making a second movie!
Suppose that Bill did manage to kill It - how would that mend his relationship with his parents? Georgie would still be dead, wouldn't he? You've got to remember that Bill is only 10 years old. At such a young age, you can't fully comprehend the reality of life and death. Ultimately, Bill rationalised in his mind that somehow killing It would bring back his brother - which was the only way of winning his parent's love back.
But, obviously, Georgie is dead (which Bill eventually comes to terms with).
As such, the answer is no: Bill wasn't able to repair his relationship with his parents. The novel seems to indicate this (albeit, not explicitly) too.
