Radios she could figure out easily rank higher. Some features that are labeled as such tend to help increase this rating number. Having to scroll though a menu just to turn the volume up or down brought the rating down. Since I don't know of any truly water proof FRS radios to compare to, this rating is a determination of how susceptible to water intrusion damage a radio would be if I were outside in the rain with it. I looked at the way it is built.
Gaskets are a help, but only if the battery pack and buttons or knobs are sealed too.
GMRS Radio Compatibility. Since the Family Radio Service shares its first seven channels with the general Mobile radio Service 'odd' simplex frequencies, it is natural to expect that a GMRS radio can communicate with an FRS radio. FRS radios that have too narrow an IF bandwidth cut out when listening to a louder GMRS transmission. Also, FRS radios that use 'companding' do not work well with GMRS radios. Then the receiver expands the audio to try and restore the sonic depth and openness to the compressed audio.