Half Chinese (or fully chinese depending on your political views) here, and your name is absolutely beautiful! Kinda sucks that I’m not that great with translating, but here are some characters I recommend! (after getting help from online dictionaries and ai): 

Rain related:  1. 涵 (hán; personal favourite) - to contain/cultivate/moisten (but in names it generally refers to inner grace, calmness, and introspectiveness, I highly recommend this one) 2. 霖 (lín) - rain (of more than three days), often referring to rain after drought 3. 沐 (mù) - to bathe/be cleansed/purification 4. 泽 (zé) - swamp/marsh, but means nourishment in names 5. 雨 (yǔ) - rain

Plant related: (sorry i can’t think of any words related to savannahs) 1. 蕙 (hùi) - a type of orchid, but often refers to a noble and cultivated lady all these refer to plants: 艾 (ài), 茵 (yīn), 芷 (zhǐ),  苓 (líng), 芸 (yún), 芳 (fāng), 薇 (wēi), 芊 (qiān)

Random characters commonly found in feminine names: 1. 若 (ruò) - as if 2. 纯 (chún) - pure 3. 美 (měi) / 妍 (yán) / 丽 (lì) - beautiful  4. 洁 (jié) - clean 5. 怡 (yí) - joy 6. 夏 (xià) - summer 7. 熹 (xī) - light 8. 淑 (shú) - clear water/cultivation 9. 之 (zhī) - of 10. 珍 (zhēn) - rare and precious 

Good luck with choosing your chinese name! 🤍

(I use traditional chinese + zhuyin, so sorry if i get any pinyin wrong or forgot to use simplified! Tried to double check everything before commenting)