Default transliteration · Sarah
莎拉 is not a name a native would pick
If an English teacher, a form, or a 'Chinese names for girls' list gave you 莎拉, they gave you the dictionary row for Sarah. They also sat you one tone away from salad.
What 莎拉 actually is
莎拉 romanizes as Shālā. It is not a 百家姓 surname plus a given name. 莎 and 拉 are foreign-name syllables. The string exists so a newscaster can pronounce Sarah. That is a useful job. It is not a name.
The salad problem
沙拉 means salad. 莎拉 is the personal-name spelling. Same shape in the ear. This is the most famous food collision in the English-to-Chinese classroom pipeline. The system did it at scale. You did not invent it.
What would Keep look like?
Not this page's job to mint you a replacement. A Keep has a real surname in first position and a given name built from characters people actually use. 陆克文 does that for Kevin. 莎拉 does not do that for Sarah.