but She was staying Behind not stronger .
(ROOT_0 (S_0 (ATS_3 (ATS_1 (CC_0 but) (NP_1 (PRP_0 She))) (VP_3 (VBD_1 was) (VP_2 (VBG_0 staying) (PP_2 (IN_0 Behind) (NP_6 (RB_1 not) (JJR_0 stronger)))))) (DOT_0 .)))