You looking for something like this:
2017 Lenovo Ideapad 14-inch Premium Performance Laptop, Intel Dual-Core Processor up to 2.48 GHz, 2GB RAM, 32GB SSD, Webcam, Bluetooth, HDMI, 802.AC, Windows 10, Free Office 365 1-year ($70 Value)
You could go cheaper with what ^^^ said "chromebook"
You're guranteed to find a PC or Laptop around those prices. Ask your moms what she really using it for. If it's just facebook and checking her email then she don't need anything >= 300. Look for cheap laptops that you can replace the hard drive for SSD to make it faster. I'll write more when I...
If I can struggle through this comp sci degree then you can bro mind you I hate school, I hate life, and I'm only finishing because I came to far to quit. yo ***** *** better finish.