puppy chewing on paws?

We have a three month old puppy, we've only had her about a month and of course she's teething like crazy. We are having good progress redirecting her to chew on toys, bones, and ice instead of everything else she can get her mouth on. However, sometimes she'll settle in on the couch with us and start chewing on her paws. It almost looks like she's chewing on her nails specifically.

I've had an adult dog in the past chew and lick a worry spot on his paw, so that there wasn't any fur in that area. In his case, it was clearly anxiety. We worked on adding more exercise and enrichment to his daily life to address the worry spot.

Should I be concerned about a pup doing something similar? Is she anxious, or just teething? How can I tell the difference?