It'll be better if she will just push her younger self to Seto-senpai since she now had a clue that her senpai was interested in her back then. Maybe that's the way to get back to her timeline,
and to make sure that her future self will be happy in the process.

Also, since her senpai is already single at her current timeline, it wouldn't be bad to ask her about how she feels back when they were in high school. Knowing that Seto-senpai WAS interested in her, she can still confirm that at present. Who knows, she might have her chance even on their current timeline!