I have been looking for an upgrade for my mum for a few months now and a few weeks ago I finally purchased the Xiaomi Redmi 3s Prime. (in most of the contents below, the 3s and the 3s Prime are used interchangeably – the only difference between the models is that the prime model also has a finger print reader.).
The Xiaomi Redmi 3 series of phones (I will explain the wording better later) have 5 inch displays, come in 2GB RAM/16GB storage or 3GB RAM/32GB Storage variants and more or less identical design, 720p IPS displays, 13 mega pixel camera and the later models also come with fingerprint readers. They use the MIUI variant of android. My phone came with MIUI 8 pre installed.