she's innocent to Hunters true plans. she knows he's a pervert now, but not his goals.
she can still be used to trick sterling, even if she didn't mean too.
remember the bad end with Eva where Hunter tricked Ophelia to buy time for him, by telling Ophelia that Brenna was looking for sterling?
this can be used with Tif too, but more directly. Something Like, hey Tif, "you're off for the whole day, BUT you have to spend it with sterling". that sounds like a great trade for Tif and she is helping Hunter while being innocent.
edit: or actually, Hunter tells Tif it's Sterling's birthday. then she has a reason to be nice to him all day. then for the reveal, Sterling says something like "this day has been great, but why?". Tif then reveals Hunter told her it was Sterlings birthday. Hearing it was Hunters plan, he already knows what is going down.
just an examples.