Doctor Who

There were episodes from the old series which had a story set in Gallifrey in which there actually were a few female Timelords.... The term "Timelord" is not meant to be taken literally....

 

So, yes, there is no real reason why the Doctor could not be a female....

But for example Romana was a Time Lady, so why would there be different terms if it wasn't meant to be taken seriously...

Also, bit of a coinsidence how there were ten male doctors on the trot...