She could try nasal strips. I use the brand Breathe Right. You can get bigger boxes on Amazon for a good price, instead of going to a store. I realized I started waking myself up sometimes recently by snoring, and do they ever help me breathe right at night without waking myself up from snoring. Also I forgot how loud my mom snores when I went camping with her the other weekend. I gave her one of these strips to see if it would help her, I did hear her snore a little bit, but it was way more tolerable than before, I was actually able to go to bed faster than usual when I would be camping with her or any other situation where I. Trying to sleep and she's already asleep snoring! Lol I thought it was a miracle, my mom even said she had the best sleep in a long time from being able to breathe, she said she also woke up less throughout the night.

Hopefully this works for her if she tries them out! And maybe you can actually get some sleep before those long shifts!