、、。
Let me guess — Taeko got scared and tried to drag Yuri down with her.
Literal
Anyway, Taeko-[polite-さん] [subj-が] scared-[become-て], Yuri-[polite-さん] [also-も] travel-companion [to-にしようとした] [copula-んでしょ].
どうせ here is the cynical 'as expected / of course' framing — the speaker is confident they already know the answer. 怖がる is the 'showing signs of being scared' form of 怖い, required when describing someone else's fear (Japanese reserves bare 怖い for the speaker's own fear). 道連れ 'travel companion' is used figuratively for 'someone dragged into one's fate' (especially something negative). ~にしようとした is the volitional + とする frame 'tried to make into X.' んでしょ (contracted from のでしょう) is a confirmation-seeking ending.