I tweaked the translation. I’m pretty sure she’s saying she’s a “penis support girl” instead of “I’ll guide it in”. I also tweaked the other line so she’s addressing senpai, not sensei.
‘Penis support girl’ is a weird phrase. Could someone confirm the translation, or maybe suggest a better term?
I’m a p◯nis support girl. ♥I'll cheer for senpai while he does his best. ♥