What has her sexuality got to do with all the things she achieved?
I can see what you mean and why it could be thought of as irrelevant.
However, a woman born in the early 1800s would have been expected to be compliant, obey her father, marry at a young age and, if lucky, have a family. None of her own possessions would have belonged to her, they would have belonged to her husband, even her own children would have belonged to him. She would have been subjugated.
Amedlia must have had a very strong personality to break the mould, refuse to conform to the life that was expected of her and become an explorer.
It wouldn't have mattered if she had been a gay man because he could have married, made a woman miserable and still led a life of adventure.