== American English == They are both grammatically correct and also natural sounding. Good job. :) You can also write these as the following in American English: 1. I was the only one that / who she had until she died. 2. I was the only one that / who was with her until she died.

Hello again Pelin, The difference here is in meaning. 1st sentence: You were her only family member/friend until the time she died. 2nd sentence: You were the only one who was at the same place, at the time she died. Hope that helps.