Stranger King by Nadia Hutton

Lena lives in British Columbia and is a "Daywalker".  This means she's goes outside during daylight to do her duties.  It pays well but the radiation is high during day so you pay for it with your body.  Still, it's what she wants to do, not follow in her father's footsteps and become part of the military.  She doesn't know when she leaves that she will never see him again...

Edge Science Fiction and Fantasy Publishing gave me the opportunity to read this book for review (thank you).  It will be published March 14th.

She's just barely getting the routine down and learning her job when aliens land.  They attack the coast first, but it's not long before they are heading inland.  The humans are nothing to them, they came for our resources.  Consequently, they don't mind killing people.  Some of them do have an interest in biological consequences of mixing the races.  Sounds to me like an even better reason to run...

You follow Lena through the years after the aliens arrival.  The humans had their own wars before they arrived and most of the land is in shambles or is unsafe.  That made them easy to raid.  The superior power of the aliens took care of any protesters.  Now the remainder of the humans are hiding in air raid shelters and using the supplies stored there.

The most ironic part is that one of the aliens is sent to communicate them and learn about them.  Lena saves him from being killed because their doctor needs his blood to work on antidotes for the various plagues that have sprouted up.  She hates him though and tells him so.  She never expected to change her mind...