Why does my IPhone stay at 2% to 7% charge when the adapter is plugged in?

So yes, it is not really my iPhone its my mom's iPhone and she said she dropped it in the toilet last night and she picked it up right away. Now the following morning the phone was still charging and I still used it to browse some stuff. Later in the afternoon it won't charge. The battery stays at 2% to 7% and when you plug the charger in the charging won't go up it just keep getting down. So when unplug the charger the phone will turn off it it will show the battery logo with the red spot in the left, but then the phone will turn on after 3 minutes and it'll do the same thing over again when you plug it back on. I really need a definite answer please because I feel sorry for my mom. All the time and effort she put on working for hours just to buy that phone won't just pay off.

It should have been turned off immediately after going in water and left off for several days. You could try turning it off and putting it in dry rice and leaving it for a few days. If lucky it will dry out and work again. Beyond that you can only hope it just needs a new battery. You can go to iFixit.com for video tutorials on replacing the battery.

Hopefully it works out. I would recommend strongly going on Amazon and getting a waterproof case if it gets working again. Otherwise recommend to your mother to get one of those waterproof Android phones. Hopefully the iPhone 6 will be waterproof.

It should have been turned off immediately and let dry for at least a day. Android phone are not waterproof but they are water resistant big difference