You know who's quite underrated in Doctor Who fandom? Adelaide Brooke.
I mean, look at her. She's capable, clever, brave, and makes her own choices 100% of the way. She makes the choice to focus on her life's ambition instead of staying on Earth with her daughter...she's a mother whose motherhood is only a tiny part of her character, and she's not punished for it! She even outright says that the sacrifices she made were worth it, to stand on Mars...a mother, a grandmother, turning down traditional motherhood? And everyone's fine with that? Good lord!
She has no romantic interests whatsoever, not in the Doctor nor in anyone else...we don't even know who fathered her children. But she has 'starlight in her soul' the same way the Doctor does, and he completely respects her. And her crew respects her, and her family respects her, and her planet respects her, and even the bloody Daleks respect her! Yet (unlike the Doctor in this episode) she in turn respects them, and calls the Doctor out on his labelling Yuri and Mia 'little people'. Sure, other people (Donna, Rory, River) have tried to point out the Doctor's destructive nature, but she actually succeeded in making him rightly ashamed of himself.
In fact...she's completely the hero of The Waters Of Mars, more so than the Doctor is. She tells the Doctor that she followed the Daleks into space not for revenge ("What would be the point of that?") but to learn. She's compassionate enough not to instantly shoot her possessed crew members, or to shoot the Doctor come to that. And (most importantly) her decision to die shaped the future of not just Earth, but the whole universe. Even though she's initially desperate to survive, she knows what the Doctor is doing is wrong, and if fixing that means her death so be it. Hey...in this episode, the whole universe is saved by a woman taking back a choice the Doctor tried to make for her!
So yeah. She's a pretty darn feminist character, I reckon, and that's good to see. Message ends!