What does the fetch new data feature on my iPhone mean?

I noticed that my options for that feature are:

Automatically
Manually
Hourly
Every 15 minutes
Every 30 minutes

How does that affect my phone?

You should contact Apple. They made the phone, after all.

Fetch new data is when the phone checks the server on it own to bring in new data (fetching it).

It could make battery life worse over time. Not terribly worse though.

Try calling her and ask. It may have been simply inadvertently set to block texts. An Easy Fix!