Correct answers
Google maps definitely uses data. Make sure she doesn't have satellite view turned on for maps, that increases use a lot for the detailed satellite photos. Just have her put it in straight map mode. There is also a new feature in Google maps so that you can download the map and use it offline so you don't need to keep using data for the same drive. Finally it is my experience that Apple maps uses less data than Google maps, so if you can have her try that. Also see the tips below that may be helpful. Sounds like she is using you for her internet service provider, rather than getting internet at her place.
Some info to try on the LG V10:
To turn on, set, or turn off the data usage indicator, follow these steps:
Part A
- From any home screen, tap Apps.
- Tap Settings.
- Tap Mobile data.
- Choose from the following options:
- Turn on a data usage limit
- Select the Limit mobile data usage check box. A new horizontal red bar appears in the graph.
- Touch the red bar and slide up or down to the desired data amount. When you reach this data amount, your data connection will be automatically disabled.
- Set the data usage limit
- Touch the red bar and slide up or down to the desired data amount.
- When you reach this data amount, your data connection will be automatically disabled.
- Turn off a data usage limit
- Clear the Limit mobile data usage check box.
- The red bar will disappear from the graph.
- Set the usage warning
- Touch the orange bar and slide up or down to set the data usage warning.
- This will not automatically disable your data connection; select a very high value to avoid receiving a warning.
- Turn on a data usage limit
Part B
To view how much data certain apps are using, follow these steps:
- From any home screen, tap Apps.
- Tap Settings.
- Tap Mobile data.
- Scroll down to view a list of apps with data usage.
- Tap an application to view more details.
If you are on a rather recent Verizon plan, there is no data roaming within US borders. When you see a large discrepancy in data, one place to look first is video. Does she stream youtube or something else? Most phones you can find out what app is using the data, plus on My Verizon it gives you an idea of what type of data is being used so check that out and report back. I know my wife regularly uses 3 x the data I use because she like to listen to music on Youtube in the car, even though she is not watching the video, it eats it up fast. As Snn5 indicates, she should be connecting to wifi whenever possible.
I really thought I was going to see the data on why your girlfriend is insane 
Google maps definitely uses data. Make sure she doesn't have satellite view turned on for maps, that increases use a lot for the detailed satellite photos. Just have her put it in straight map mode. There is also a new feature in Google maps so that you can download the map and use it offline so you don't need to keep using data for the same drive. Finally it is my experience that Apple maps uses less data than Google maps, so if you can have her try that. Also see the tips below that may be helpful. Sounds like she is using you for her internet service provider, rather than getting internet at her place.
Some info to try on the LG V10:
To turn on, set, or turn off the data usage indicator, follow these steps:
Part A
- From any home screen, tap Apps.
- Tap Settings.
- Tap Mobile data.
- Choose from the following options:
- Turn on a data usage limit
- Select the Limit mobile data usage check box. A new horizontal red bar appears in the graph.
- Touch the red bar and slide up or down to the desired data amount. When you reach this data amount, your data connection will be automatically disabled.
- Set the data usage limit
- Touch the red bar and slide up or down to the desired data amount.
- When you reach this data amount, your data connection will be automatically disabled.
- Turn off a data usage limit
- Clear the Limit mobile data usage check box.
- The red bar will disappear from the graph.
- Set the usage warning
- Touch the orange bar and slide up or down to set the data usage warning.
- This will not automatically disable your data connection; select a very high value to avoid receiving a warning.
- Turn on a data usage limit
Part B
To view how much data certain apps are using, follow these steps:
- From any home screen, tap Apps.
- Tap Settings.
- Tap Mobile data.
- Scroll down to view a list of apps with data usage.
- Tap an application to view more details.