Did you (her) try using GetJar, 1Mobile, SlideME or Amazon app market (works only in USA)? All of them are very easy to install, simply use the built-in browser to download and install their apk.
Skype will likely NOT do video. I tried the latest version a few days ago to see if any of the updates would help.
On my Coby MID-1125-4G the older version of Skype will do voice(only) calls fine. I use a headphone, and the mic & sound quality was pretty good. I got that version from GetJar - it IDs my COBY tablet and seems to load the best version. The newest version of Skype would not do voice calls on my COBY tablet.
There are also other video-products should you require it. I'm not sure which one(s) if any work with the COBY. You'd have to test each one.