大丈夫 私もだから
大丈夫 私もだから: one 「も」 shows all her cards
The function of 「も」 in Japanese is "you and I are in the same category", and what that category is depends entirely on context. Here the previous line is「1周目じゃないよね?」, so 「私も」 = "I'm not on my first lap either."
Why not say it in full: spelling it out (「私もやり直してるんだよ」) would sound like explaining or selling something; saying only 「私も」 assumes the other person already understands, and that in itself is a kind of closeness. Mari has waited all these years, and this moment of "no explanation needed" is exactly what she wanted.
⚠ 「だから」 here doesn't mean "therefore"; it is the sentence-final "because..." (a spoken shortening of 〜んだから), giving the reason for the previous「大丈夫」.


















