I don't think it's any issue with giving birth to a "girl" especially since the doctor didn't say to just make him a boy but rather for him to decide as he grew up. I'm pretty sure what's happening here is Alex is intersex, meaning he was born with both male and female traits, and can't be explicitly identified as either sex at birth. This is incredibly rare but possible and has happened in real life on multiple occasions.
I don't think it's any issue with giving birth to a "girl" especially since the doctor didn't say to just make him a boy but rather for him to decide as he grew up. I'm pretty sure what's happening here is Alex is intersex, meaning he was born with both male and female traits, and can't be explicitly identified as either sex at birth. This is incredibly rare but possible and has happened in real life on multiple occasions.