I like to make some theories about some plot holes here, so if you want hear me out. For why there were not any guards around her, probably she sneaking to drink with her friend, so no guards know she was leaving her home. For how easily she died, it was because of alcohol. Some human when drunk can die easily by accident even a strong human, because their organ not working perfectly. For how she could designed outfits even her memories still not return. There are some anecdotes (forgot where I saw them) where when a pianist reincarnated, when he a child, his body remember how to play piano beautifully even he play it at his first time, but he don't know how he learn to play piano (in this case, his memories from before he reincarnated still not or never return)