Hi, need help to suggest a phone to give to my mom

1. Brand: Samsung (she already used to my dad's S4)
2. Budget: ~RM500
3. Specs: Main function is for whatsapp. As I bet she does not know how to clear the memory which will later cause the phone to lag, anything that can help to reduce the lag?
4. Type/Size: Any

Thanking in advance.

double post. stupid mouse

This post has been edited by overruled23: Mar 30 2016, 10:56 PM