With all the misunderstandings brewing around them, Belle and Eli weren't able to reconcile from their previous fight. In addition, since they promised Jillyanna that they would visit together, Belle had to pretend that everything was fine between her and Eli.
Last time, she asked if it would be fine to borrow Hapi to look after Neon and if she could just pay her for that day. However, she no longer brought up this conversation and decided to ask Jackson to look after her brother instead.
When Eli picked her up from her house and saw Jackson playing a game of tag with Neon, he no longer asked why the man was there.
Thus, upon arriving in front of Jillyanna's home, even though they tried their best to act like everything was fine, the security guards were still able to see through their disguise. So, it was no longer a surprise that Jill could tell the couple was fighting. She didn't point it out, though.