Name: Remnant Population
ISBN: 9780345462190

Elizabeth Moon

Refusing to leave her only home to board the cryo ships, Ofelia hides, content to live alone on an abandoned planet, but when new settlers arrive and are slaughtered by unknown stone age aliens, she takes it upon herself to save the aliens from Earth's wrath. Reprint.

Remnant Population

Janice Hopper

** spoiler alert **
           It's rare to find a book with an older female protagonist. Ofelia, who's in her 70's, arranges to be left behind when her colony is evacuated from the planet they were colonizing. It would cost her family extra to transport her because of her age, and her odds of surviving cryogenic-transport were low anyway. Ofelia decided she'd rather stay on the planet and live out her remaining years in peace and quiet. She thought she'd be able to tend her gardens and do what she wanted without pressure from nagging relatives, or responsibility for children. She assumed she'd die alone, and was ok with that. 

Things didn't work out quite as she planned. 

I liked the freedom Ofelia felt when she was no longer constrained by her society's expectations of her. Her dismay at finding she wasn't really alone on the planet had as much to do with realizing she would again have demands on her time as finding out there was another sentient species nearby. But when she found herself in a protector role again, she stepped into it like the caregiver she'd been all her life. 

I'm not sure I buy the quick rise to sentience of the aliens, or their relatively quick acceptance of her. But it makes a good story. The indigenes are interesting and rather winsome, and more than a match for the humans who return to the colony world.