、。
She felt sick and crouched down on the ground.
Literal
She [topic-は] mood [subject-が] became-bad, ground [on-に] crouched-down.
気分が悪くなる ('feel ill, feel sick') is the standard idiom for nausea or general unwellness — 気分 ('mood, feeling') taking the い-adjective 悪い ('bad') in its く-adverbial form plus なる ('become'). The construction is productive: 気分がよくなる ('feel better'), 気分が落ち着く ('feel calmed'), 気分が乗らない ('not in the mood'). かがみこむ is a compound verb (屈む 'bend, stoop' + 込む 'go deeply into') for crouching down low, often suggesting sudden distress or trying to make oneself small. The に on 地面 marks the location reached by the crouching motion.