I like where this is going! What with Kayla making more and more friends outside of River, and these guys wondering if she may not only help them reach the surface, but help them adjust to it as well. Is she going to be this fic's version of Frisk? I suppose I shall find out! ;)

Just a couple of notes/questions:

1. Doggo isn't Dogaressa's husband. Dogamy is. (Though, typing that out now, I think I can see why you got confused.)

2. River Person taught Kayla sign language, right? To disguise her voice? The story doesn't seem to show her using it. Also, how do the monsters' voices sound different from those of humans?

3. A thing with your stories in general, I think your words tend to be pretty repetitive. Maybe try writing everything like you normally would, then go back and use a thesaurus. Proofreading is a good idea in general, really. After all, you do seem to have a few grammar mistakes here and there as well, though I can't remember if there was a time where I was unable to figure out what you meant.

pretty cool

SUPER FANTASTIC STORY! CAN'T WAIT FOR THE NEXT ADVENTURE!

Fantastic story, Amiga! Loved it all the way through! :)

Aww! Such a sweet ending!

Nice

Wow! Amazing way to break the barrier!

OH MAN THE BARRIER'S GONE!

WHAT'S GOING TO HAPPEN?! CAN'T WAIT CAN'T WAIT!

Yay

Whoa! Awesome! Can't wait for the epilogue! Sweet chapter!

Spooky scary skeletons...

Yay! Gaster is back!

How'd the girls restore him though?

Aww! I'm so glad little Frisk has entered the Underground. And I love that you paired Kayla with Napstablook! Blooky deserves love.

Uh oh! I wonder who the shadow is? Flowey?

Babybones...that nickname is just too cute :)