How can I figure out the culprit with internet hiccups my wife is experiencing? I'm having a hard time figuring out why my wife hates our internet connection. She says that it times out on her throughout the day. This happens both on the laptop and phone. She uses FireFox and Chrome (work and personal), and the error connecting pages show up on both. 

She is running Yosemite 10.10.2 on her mid-2011 MacBook Air and iOS 8.2 (12D508) on her iPhone 5. Both of her devices are running out of storage if that makes a difference. (There is never enough storage space for pictures of kittens.) She gets a ping of 30ms for google.com in the living room where our access point is located.

When I work from home, I do not experience any issues. My ping is at about 12-15ms for google, and I am hardwired to the router. When I'm mobile around the house, I have no issues whatsoever. I'm on a mid-2014 MacBook Pro. 

Given that this issue is a hiccup, as it comes up, and fixes itself quickly, what would be a method I can use to figure out how to fix this issue so that she has a pleasant internet experience?

NOTES:


Internet setup > Comcast -> DOCSIS modem -> ASUS router ~10 yards~
Linksys AP (running DD-WRT)
My wife is about two yards away from the Linksys router
The hiccups happen during the day and not in the evening 
The other devices on the network are our Windows 7 HTPC (sleeps during the day), DiskStation (sleeps unless it's woken up), an Android device, and an Onkyo Turner
Speedtest.net shows our connection at 120/12 MBps in during the day and 60/10 in the evening
Update to latest OS X 10.10.5 and iOS 8.4. Both the updates solve the annoying Internet issues.  The issues were frequent disconnection in regular intervals, slow Internet speed etc. In Yosemite, Apple introduced the troubling Discoveryd component for networking which was the main cause. It has been replaced in OS X 10.10.4 and iOS 8.4. Install the updates and your Internet should work properly.