Originally Posted by Dankees
Is that normal? Isn't that weird?
Yes its normal. You were on 3G and she was one Wifi. 3G uses more power than Wifi. That's why every thread about battery life states to use Wifi as much as possible. If you were on 4G it'd probably use 3x as much battery.
Also, the weaker the cell signal the more power the phone uses to try to boost the connection. So if the signal was on the low side in your house it would drain even faster.