Perhaps she should be more selective with apps she installs? Also, how would this be exclusive to Android? iOS apps can have ads on them. Even if the feature is added with an update.
The ads weren't only displaying in the app, they were appearing over other apps. This is something that simply can't happen in iOS.
How does a standard user know whether a small app to e.g. manipulate photos (as in this instance) is going to be updated a few days later to show ads when it's not running? Shouldn't an end user be able to trust Google's app marketplace to not feed them junk like this?
Perhaps she should be more selective with apps she installs? Also, how would this be exclusive to Android? iOS apps can have ads on them. Even if the feature is added with an update.